Display processing method and display processing apparatus

ABSTRACT

According to the present invention, when video resolution is changed, the TV receiver selects resolution having a priority to the graphics resolution requested by the application depending on the application types, or the TV receiver selects graphics resolution appropriate for video format resolution, thereby the TV receiver enables the clear display of graphics without causing any distortion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.60/487,938, filed Jul. 18, 2003, and also claims priority of JapaneseApplication No. 2004-167726, filed on Jun. 4, 2004.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

The present invention relates to a processing method and the like fordisplaying video and graphics, and particularly to a control forswitching image resolutions in a TV receiver and the like that receivesan interactive program through a digital broadcasting.

(2) Description of the Related Art

In recent years, a program called an interactive program has beenbroadcasted as practical usage of digital technologies. When theinteractive program is provided on air, an application described inJava™, HTML, etc. is usually included in the program. Then, thisapplication superposes information on video using graphics and/or textsfor creating one content. To execute the application, the application isdelivered to a TV receiver either through a digital wave thatdistributes the program or through a different delivery route such asthe Internet. This function is called as application download or upload.

Also, the application may be the one that displays an advertisement,etc., which is unrelated to the program or content, at a corner of ascreen on the TV receiver. Such an application is created by a venderdifferent from a vender who creates an application for content, and theapplication here is independently downloaded from the content andexecuted on a TV receiver.

In general, in the interactive broadcasting like this, it is preferablethat the application provides information along with graphics resolutioncorresponding to video resolution. This is because, if graphicsresolution different from the resolution for the video is used, anenlargement and reduction process needs to be executed to unify bothresolution when the information is output on a display apparatus.However, when this process is executed, pixel dithering, etc. occur,which make it difficult to keep a beautiful display.

In the meantime, in compression technologies for digital video, such asan MPEG technology, there is a huge difference in a bandwidth necessaryfor data transfer if video resolution varies. Because of this, in thedigital broadcasting, it is necessary, from a viewpoint of saving theband for data transfer, to broadcast a program with appropriate videoresolution according to its program content.

Then, a combination of the video resolution and the graphics resolutionbecomes an issue at this point.

That is to say, if the video resolution of a channel that has beenselected up to a certain point is different from the video resolution ofanother channel that is newly selected, a beautiful picture can not beexpected unless these graphics are displayed with the graphicsresolution respectively corresponding to each of the video resolution.The most preferable selection is to use the graphics resolutionequivalent to the video resolution. However, depending on a TV receiver,such graphics resolution can not be used due to some reasons such as acost. If that is the case, it is supposed to select the graphicsresolution that can provide a display as beautiful as possible.

As one of conventional technologies for realizing selection of thegraphics resolution, there is a HAVi specification. HAVi(http://www.havi.org/) stands for Home Audio Video Interoperability. Itstipulates a specification that allows an application operated on a TVreceiver controlling the graphics resolution and the video resolution.In the HAVi specification, an API is provided to control the graphicsresolution in a class called HGraphicsDevice. When the applicationdesignates ideal graphics resolution to be used, it is possible toprovide and use the resolution closest to it from the graphicsresolution available in the TV receiver.

In the meantime, graphics display materials with resolution according toan image format are made available in advance. And, when the videoresolution is changed, its image format is determined from videopackets, and graphics display materials according to the image formatare displayed. By doing so, the display materials with the same qualityand in the same size can be consistently shown (See Japanese Laid-OpenPatent application No. 2000-23061, Japanese Laid-Open Patent applicationNo. 2002-247465, Japanese Laid-Open Patent application No. 10-124021,and Japanese Patent No. 3315557, for example).

However, in the HAVi specification, graphics resolution, which is theclosest to the desired one, is simply selected from the graphicsresolution available in the TV receiver. It does not take account of anideal combination of the graphics resolution with the video resolutionreceived currently.

Also, in the above patent documents and the like, when the videoresolution is changed, it is possible to show the display material withthe same quality and in the same size on the TV receiver. However, itdoes not consider a layout of the application display.

SUMMARY OF THE INVENTION

The present invention aims at providing a display method and the likecapable of automatically selecting appropriate graphics resolution,taking account of an ideal combination with video resolution currentlyreceived by the TV receiver, notifying and providing it to anapplication so that a beautiful display can be achieved without causingany distortion of graphics display even if the video resolution isswitched.

The present invention also aims at, when the video resolution ischanged, providing a display method and the like that prioritizes andselects graphics resolution requested by an application depending on atype of the application or selects graphics resolution according toresolution of a video format so that it can show a beautiful displaywithout causing any distortion of graphics display even if the videoresolution is switched.

In order to solve the above problem, the present invention is a displayprocessing method comprising: a graphics resolution change requestaccepting step of accepting, from an application, a resolution changerequest for changing a resolution of graphics; a graphics resolutionchanging step of changing the resolution of the graphics in response tothe resolution change request; a video enlarging and reducing step ofenlarging or reducing received video so that said video and the graphicswhose resolution has been changed in the graphics resolution changingstep are composed; and a composing and outputting step of composing thegraphics and the video, and outputting a resultant of said composition,wherein in the video enlarging and reducing step, in the case where aresolution of the received video is changed, in order to compose thevideo whose resolution has been changed and the graphics whoseresolution has been changed in the graphics resolution changing step, itis determined whether to enlarge or reduce the received video dependingon the change in the resolution of said video, and said video isenlarged or reduced according to said determination, and in thecomposing and outputting step, the graphics and the video which has beenenlarged or reduced in the video enlarging and reducing step arecomposed, and the resultant of said composition is outputted.Accordingly, in the case where a request for changing the resolution ofthe graphics is received from the application and where the resolutionof the received video has been changed, such video is enlarged orreduced based on the resolution of the graphics. This makes it possibleto compose the graphics and video without changing the resolution of thegraphics required by the application, and therefore to display theresultant of said composition, with the quality of the graphicsmaintained.

Here, the display processing method may further comprise a graphicsresolution change permitting step of granting permission to change theresolution of the graphics to the application that makes the resolutionchange request, wherein in the graphics resolution change requestaccepting step, the resolution change request is accepted from theapplication that has been granted the permission. Accordingly, since agraphics change request from an application without permission will notbe accepted, only an appropriate application is allowed to change theresolution of the graphics.

Moreover, in the graphics resolution change permitting step, in the casewhere a resolution change request for changing the resolution of thegraphics is received from an application that is different from theapplication that has been granted the permission, permission to changethe resolution of the graphics may be granted only to either of saidapplications. Accordingly, it becomes possible to circumvent thesituation in which appropriate processing cannot be performed because ofanother application making another graphics resolution change request.

Also, in the graphics resolution change permitting step, the permissionto change the resolution of the graphics may be granted according topriorities that are given in advance to the respective applications.Accordingly, it becomes possible to grant permission to change theresolution of the graphics to an optimum application.

Furthermore, the display processing method may further comprise a stepof enlarging or reducing a still image that is generated based on framedata provided by the application so that said still image and thegraphics whose resolution has been changed in the graphics resolutionchanging step are composed, wherein in the composing and outputtingstep, the graphics, the video, and the still image are composed, and aresultant of said composition is outputted. Accordingly, it becomespossible to compose the graphics, video and still image without changingthe resolution of the graphics required by the application, andtherefore to display the resultant of said composition beautifully, withthe quality of the graphics maintained.

Also, the present invention is a display processing method comprising: agraphics data storing step of storing graphics data designated by anapplication into a graphics data storing unit that is assigned a firstgraphics resolution; a video decoding step of decoding received video; avideo data storing step of storing video data into a video data storingunit that is assigned a first video resolution, said video data beingobtained by the decoding of the received video performed in the videodecoding step; a composing and outputting step of composing the graphicsdata stored in the graphics data storing unit and the video data storedin the video data storing unit, and outputting a resultant of saidcomposition, a graphics resolution change accepting step of accepting,from the application, a second graphics resolution that is used tochange the first graphics resolution assigned to the graphics datastoring unit; a graphics resolution changing step of changing the firstgraphics resolution assigned to the graphics data storing unit to thesecond graphics resolution that is accepted in the graphics resolutionchange accepting step; a video resolution determining step ofdetermining a second video resolution to be assigned to the video datastoring unit, depending on a current graphics resolution assigned to thegraphics data storing unit; and a video resolution changing step ofchanging the first video resolution assigned to the video data storingunit to the second video resolution determined in the video resolutiondetermining step, wherein said video resolution determining step andvideo resolution changing step are executed on one of the followingoccasions: the first graphics resolution assigned to the graphics datastoring unit is changed in the graphics resolution changing step; andthe first video resolution of the video received in the video decodingstep changes. Accordingly, in the case where a request for changing thegraphics resolution of the graphics data is received from theapplication and where the video resolution of the received video datahas been changed, the video resolution of the received video isdetermined based on the graphics resolution. This makes it possible tocompose the graphics data and video data without changing the graphicsresolution required by the application, and therefore to display theresultant of said composition, with the quality of the graphics datamaintained.

Here, the display processing method may further comprise: a still imagestoring step of storing a still image into a still image storing unitthat is assigned a first still resolution; a still resolutiondetermining step of determining a second still resolution to be assignedto the still image storing unit, depending on a current graphicsresolution that is assigned to the graphics data storing unit; and astill resolution changing step of changing the first still resolutionassigned to the still image storing unit to the second still resolutiondetermined in the still resolution determining step, wherein said stillresolution determining step and still resolution changing step areexecuted on one of the following occasions: the first graphicsresolution assigned to the graphics data storing unit is changed in thegraphics resolution changing step; and the first video resolution of thevideo received in the video decoding step changes, and in the composingand outputting step, the graphics data stored in the graphics datastoring unit, the video data stored in the video data storing unit, andthe still image stored in the still image storing unit are composed, anda resultant of said composition is outputted. Accordingly, it becomespossible to compose the graphics data, video data and still imagewithout changing the graphics resolution required by the application,and therefore to display the resultant of said composition beautifully.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects, advantages and features of the invention willbecome apparent from the following description thereof taken inconjunction with the accompanying drawings that illustrate a specificembodiment of the invention. In the Drawings:

FIG. 1 is a configuration diagram of a cable TV system in an embodiment1 according to the present invention;

FIG. 2 is an example that shows how to use a frequency band used forcommunications between a head end and a terminal apparatus in the cableTV system according to the present invention;

FIG. 3 is an example that shows how to use a frequency band used forcommunications between a head end and a terminal apparatus in the cableTV system according to the present invention;

FIG. 4 is an example that shows how to use a frequency band used forcommunications between a head end and a terminal apparatus in the cableTV system according to the present invention;

FIG. 5 is a configuration diagram of a terminal apparatus in the cableTV system according to the present invention;

FIG. 6 is an example of an outside view of a terminal apparatus in thecable TV system according to the present invention;

FIG. 7 is a configuration diagram of a hardware configuration of POD504according to the present invention;

FIG. 8 is a configuration diagram of a program configuration stored inPOD504 according to the present invention;

FIG. 9 is a configuration diagram of a packet defined in an MPEGstandard;

FIG. 10 is an example of an MPEG 2 transport stream;

FIG. 11 is an example of an outside view for a case that an input unit513 is realized on a front panel;

FIG. 12 is a configuration diagram of a program configuration stored ina terminal apparatus 500 according to the present invention;

FIG. 13 (1) is an example of a display 509 according to the presentinvention;

FIG. 13 (2) is an example of the display 509 according to the presentinvention;

FIG. 14 is an example of information stored in a secondary storage unit510 according to the present invention;

FIG. 15 is an example of information stored in a primary storage unit511 according to the present invention;

FIG. 16 is a pattern diagram that shows content of PAT stipulated by anMPEG 2 standard according to the present invention;

FIG. 17 is a pattern diagram that shows content of PMT stipulated by theMPEG 2 standard according to the present invention;

FIG. 18 is a pattern diagram that shows content of AIT stipulated by aDVB-MHP standard according to the present invention;

FIG. 19 is a pattern diagram that shows a file system transmitted in aDSMCC method according to the present invention;

FIG. 20 is a pattern diagram that shows content of XAIT according to thepresent invention;

FIG. 21 is an example of information stored in the secondary storageunit 510 according to the present invention;

FIG. 22 is an example of a Z order of planes according to the presentinvention;

FIG. 23 is a combination example of the Z order of planes according tothe present invention;

FIG. 24 is an example of a flowchart related to a display process for avideo according to the present invention;

FIG. 25 is an example of a flowchart related to a display process for astill according to the present invention;

FIG. 26 is an example of a flowchart related to a display process for anOSD according to the present invention;

FIG. 27 is an example of a flowchart related to a composing process fora video, a still and an OSD according to the present invention;

FIG. 28 is an example of a display image of enlargement and reductionaccording to the present invention;

FIG. 29 is an example of a display image before a composing processaccording to the present invention;

FIG. 30 is an example of a display image after the composing processaccording to the present invention;

FIG. 31 is an example of a configuration diagram of a resolutionswitching unit 1205 f according to the present invention.

FIG. 32 is an example of a combination available to be displayed betweenplanes according to the present invention;

FIG. 33 is an example of a process flowchart of a resolution selectiondeciding unit 3105 for a case there is a resolution change request of anOSD plane according to the present invention;

FIG. 34 is an example of a process flowchart of the resolution selectiondeciding unit 3105 for a case there is a resolution change request of avideo plane according to the present invention;

FIG. 35 is an example of a flowchart of the resolution selectiondeciding unit 3105 for a case there is a resolution change request of astill image plane according to the present invention;

FIG. 36 is an example of a flowchart of the resolution selectiondeciding unit 3105 for a case resolution is different from the one of avideo format that has been previously decoded according to the presentinvention;

FIG. 37 is an example of a flowchart of the resolution selectiondeciding unit 3105 for a case resolution is different from the one of avideo format that has been previously decoded according to the presentinvention;

FIG. 38 is an example of a screen for an application program where avideo format change is preceded according to the present invention;

FIG. 39 is an example of a screen for an application program where anOSD resolution is preceded according to the present invention;

FIG. 40 is an example of a configuration diagram of a resolutionswitching unit 1205 f according to the present invention;

FIG. 41 is an example of a configuration diagram of the resolutionswitching unit 1205 f according to the present invention;

FIG. 42 is an example of a flowchart of an optimum resolution managingunit 4106 for a case an optimum OSD resolution is registered accordingto the present invention;

FIG. 43 is an example of a flowchart of the optimum resolution managingunit 4106 for a case an optimum OSD resolution is deleted according tothe present invention;

FIG. 44 is an example of a flowchart of a resolution selection decidingunit 4105 for a case there is a resolution change request for an OSDplane according to the present invention;

FIG. 45 is an example of a flowchart of the resolution selectiondeciding unit 4105 for a case there is a resolution change request for avideo plane according to the present invention;

FIG. 46 is an example of a flowchart of the resolution selectiondeciding unit 4105 for a case there is a resolution change request for astill plane according to the present invention;

FIG. 47 is an example of a flowchart of the resolution selectiondeciding unit 4105 for a case resolution is different from the one of avideo format that has been previously decoded according to the presentinvention;

FIG. 48 is an example of a flowchart of a resolution selection decidingunit 3105 for a case a resolution is different from the one of a videoformat that has been previously decoded according to the presentinvention;

FIG. 49 is an example of a set of Java program identifiers and optimumOSD resolution according to the present invention;

FIG. 50 is an example of a flowchart of the optimum resolution managingunit 4106 for a case optimum OSD resolution is registered according tothe present invention;

FIG. 51 is an example of a flowchart of the optimum resolution managingunit 4106 for a case optimum OSD resolution is deleted according to thepresent invention;

FIG. 52 is an example of a flowchart of the resolution selectiondeciding unit 4105 for a case resolution is different from the one of avideo format that has been previously decoded according to the presentinvention;

FIG. 53 is an example of a flowchart of the resolution selectiondeciding unit 4105 for a case resolution is different from the one of avideo format that has been previously decoded according to the presentinvention;

FIG. 54 is an example of a flowchart of the resolution selectiondeciding unit 4105 for a case resolution is different from the one of avideo format that has been previously decoded according to the presentinvention;

FIG. 55 is an example of a flowchart of the resolution selectiondeciding unit 3105 for a case resolution is different from the one of avideo format that has been previously decoded according to the presentinvention;

FIG. 56 is an example of a configuration diagram of the resolutionswitching unit 1205 f according to the present invention;

FIG. 57 is a diagram showing a positional relationship among the first,second, and third buffers;

FIG. 58 is a diagram showing an exemplary pattern of combinationsrelated to the Z order of the first to third buffers;

FIG. 59 is a flowchart related to processing of composing the videogenerated according to the flowchart in FIG. 24, the still generatedaccording to the flowchart in FIG. 25, and the OSD generated accordingto the flowchart in FIG. 26;

FIG. 60 is a diagram showing exemplary displayable combinations ofresolutions of three types of the buffers;

FIG. 61 is a diagram showing exemplary displayable combinations ofresolutions of three types of the buffers (continued from FIG. 60);

FIG. 62 is a flowchart showing processing performed by the resolutionselection deciding unit in the case where the OSD resolution managingunit receives a resolution change request of the current OSD buffer;

FIG. 63 is a flowchart showing processing performed by the resolutionselection deciding unit in the case where the OSD resolution managingunit receives a resolution change request of the current OSD buffer(continued from FIG. 62);

FIG. 64 is a flowchart showing processing performed by the resolutionselection deciding unit in the case where the resolution of the videoformat received by the video decoder is different from the resolution ofthe previously decoded video format;

FIG. 65 is a flowchart showing processing performed by the resolutionselection deciding unit in the case where the resolution of the videoformat received by the video decoder is different from the resolution ofthe previously decoded video format (continued from FIG. 64);

FIG. 66 is another flowchart showing processing performed by theresolution selection deciding unit in the case where the resolution ofthe video format received by the video decoder is different from theresolution of the previously decoded video format;

FIG. 67 is another flowchart showing processing performed by theresolution selection deciding unit in the case where the resolution ofthe video format received by the video decoder is different from theresolution of the previously decoded video format (continued from FIG.66);

FIG. 68 is a flowchart in the case where the OSD resolution managingunit receives a resolution change notification;

FIG. 69 is a flowchart in the case where the video resolution managingunit receives a resolution change notification; and

FIG. 70 is a flowchart in the case where the still resolution managingunit receives a resolution change notification;

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

With reference to diagrams, the following describes embodiment of acable TV system according to the present invention. FIG. 1 is a blockdiagram that shows a relationship of an apparatus comprising a cablesystem, which includes a head end 101 and three terminal apparatusesA111, B112 and C113. In the present embodiment, three terminalapparatuses are connected to one head end. However, the presentinvention may also be embodied by having a designated number of terminalapparatuses that are connected to the head end.

The head end 101 sends a broadcasting signal of video, audio and data,etc. to a plural number of terminal apparatuses, and also receives datasent from the terminal apparatus. In is order to realize this, afrequency bandwidth used for transmission between the head end 101 andterminal apparatuses A111, B112 and C113 is divided for use. FIG. 2 is achart that shows an example of the divided frequency bandwidth. Thebandwidth can be roughly divided into two types; Out Of Band (so-calledOOB) and In-Band. 5 to 130 MHz are assigned to OOB, and mainly used fordata communication between the head end 101 and terminal apparatusesA111, B112 and C113. 130 MHz to 864 MHz are assigned to the In-Band, andmainly used for a broadcasting channel that includes video and audio. AQPSK modulation method is used for OOB, and a QAM64 modulation method isused for In-Band. The modulation technology is a publicly knowntechnology, which is not so closely tied up with the present invention,so that its detailed explanation is omitted here. FIG. 3 is an exampleof further detailed use of the OOB frequency bandwidth. 70 MHz to 74MHzare used for data transmission from the head end 101, and all of theterminal apparatuses A111, B112 and C113 are supposed to receive thesame data from the head end 101. On the other hand, 10.0 MHz to 10.1 MHzare used for data transmission from the terminal apparatus A111 to thehead end 101, 10.1 MHz to 10.2 MHz are used for data transmission fromthe terminal apparatus B112 to the head end 101, and 10.2 MHz to 10.3MHz are used for data transmission from the terminal apparatus C113 tothe head end 101. By doing so, unique data in each terminal apparatuscan be individually sent from each of the terminal apparatuses A111,B112 and C113 to the head end 101. FIG. 4 is an example showing how afrequency bandwidth of the In-Band is used. 150 to 156 MHz and 156 to162 MHz are respectively assigned to a TV channel 1 and a TV channel 2,and following frequency bandwidths at intervals of 6 MHz are assigned toeach corresponding TV channel. A frequency bandwidth of 310 MHz andbigger are respectively assigned to radio channels by each 1 MHz unit.Each of these channels may also used for analogue broadcasting or fordigital broadcasting. For a case of the digital broadcasting, data istransmitted in a transport packet format based on MPEG 2 specifications,and also data for various data broadcasting can be sent in addition toaudio and video.

The head end 101 contains a QPSK modulation unit and a QAM modulationunit, etc. for sending an appropriate broadcasting signal to thesefrequency bandwidths. Also, it is considered that the head end 101 hasvarious devices related to these modulation units and demodulationunits. However, because the present invention mainly relates to terminalapparatuses, its detailed explanation is omitted here.

The terminal apparatus A111, the terminal apparatus B112 and theterminal apparatus C113 receive and reproduce the broadcasting signalfrom the head end 101. Also, these apparatuses send unique data of eachterminal apparatus to the head end 101. These three terminal apparatuseshave the same structure in the present embodiment.

FIG. 5 is a block diagram that shows a hardware configuration of theterminal apparatus. 500 is a terminal apparatus that includes a QAMdemodulation unit 501, a QPSK demodulation unit 502, a QPSK modulationunit 503, a TS decoder 505, an audio decoder 506, a speaker 507, a videodecoder 508, a display 509, a secondary storage unit 510, a primarystorage unit 511, a ROM 512, an input unit 513, a CPU 514, a stilldecoder 515, an OSD controlling unit 516, a video buffer 517, a stillbuffer 518, an OSD buffer 519, a video enlargement and reduction unit520, a still enlargement and reduction unit 521, an OSD enlargement andreduction unit 522, a composing unit 523. Also, a POD 504 is installedto and detached from the terminal apparatus 500.

FIG. 6 is a thin shaped television as one of the examples for an outlookof the terminal apparatus 500.

601 is a steel case of the thin shaped television, which has all ofstructural components of the terminal apparatus 500 in it with anexception of the POD 504.

602 is a display, which is equivalent to the display 509 shown in FIG.5.

603 is a front panel unit combining of a plural number of buttons, whichis equivalent to the input unit 513 in FIG. 5.

604 is a signal input terminal that connects a cable for sending andreceiving a signal to/from the head end 101. The signal input terminalis connected to the QAM demodulation unit 501, the QPSK demodulationunit 502 and the QPSK modulation unit 503.

605 is a POD card, which is equivalent to the POD 504 in FIG. 5. Justlike the POD card 605 in FIG. 6, the POD 504 has an independentconfiguration from the terminal apparatus 500 and is attached to anddetached from the terminal apparatus 500. Details of the POD 504 will beexplained later.

606 is an insertion slot to which the POD card 605 is inserted.

With reference to FIG. 5, the QAM demodulation unit 501 demodulates asignal which has been QAM-modulated in and sent by the head end 101according to tuning information containing a frequency designated fromthe CPU 514, and passes it to the POD 504.

The QPSK demodulation unit 502 demodulates a signal which has beenQPSK-modulated in and sent by the head end 101 according to tuninginformation containing a frequency designated from the CPU 514, andpasses it to the POD 504.

The QPSK modulation unit 503 QPSK-modulates a signal sent by the POD 504according to modulation information containing a frequency designatedfrom the CPU 514, and passes it to the head end 101.

The POD 504 has a configuration that is detachable from the terminalapparatus body 500 as shown in FIG. 6. A connection interface betweenthe terminal body 500 and the POD 504 is defined in OpenCable™ HOST-PODInterface Specification (OC-SP-HOSTPOD-IF-I12-030210) and aspecification document referred by this specification document. Here,its detail is omitted, and only the part concerned for the presentinvention is explained.

FIG. 7 is a block diagram that shows an internal configuration of thePOD 504. The POD 504 includes a first descrambler unit 701, a seconddescrambler unit 702, a scrambler unit 703, a first storage unit 704, asecond storage unit 705 and a CPU 706.

The first descrambler unit 701 receives a signal scrambled from the QAMdemodulation unit 501 of the terminal apparatus 500 and descrambles itaccording to an instruction from the CPU 706. Then, the signaldescrambled is sent to the TS decoder 505 of the terminal apparatus 500.Information necessary for decoding, such as a key, is provided from theCPU 706 as needed. To be more specific, the head end 101 broadcastsseveral paid channels. If a user subscribes this paid channel, the firstdescrambler unit 701 receives necessary information, such as a key, anddescrambles its content so that the user can view the paid channel. Ifthe necessary information, such as a key, is not provided, the firstdescrambler unit 701 does not execute the descrambling process, andsends the received signal as it is to the TS decoder 505.

According to an instruction from the CPU 706, the second descramblerunit 702 receives a signal scrambled from the QPSK demodulation unit 502of the terminal apparatus 500 and descrambles it. Then, the seconddescrambler unit 702 passes the descrambled data to the CPU 706.

According to an instruction from the CPU 706, the scrambler unit 703scrambles the data received from the CPU 706 and sends it to the QPSKmodulation unit 503 of the terminal apparatus 500.

The first storage unit 704 is made up of a primary memory, which isspecifically something like a RAM, etc. and is used for temporarilystoring data when the CPU 706 executes a process.

The second storage unit 705 is made up of a secondary memory, which isspecifically something like a flash ROM, etc., and is used for storing aprogram executed by the CPU 706, and also for saving data that shouldnot be deleted even if its power is turned off.

The CPU 706 executes a program memorized in the second storage unit 705.The program is made up of a plural number of subprograms. FIG. 8 is asample program memorized in the second storage unit 705. In FIG. 8, theprogram 800 is made up of a main program 801 and a plural number ofsubprograms such as an initialization subprogram 802, a networksubprogram 803, a reproduction subprogram 804, a PPV subprogram 805,etc.

The PPV here is an acronym of Pay Per View, which is a service to allowspecific programs such as movies to be viewed with a certain charge.When a user enters a personal identification number, his subscription isnotified to the head end 101, and its scramble is removed for viewing.The user will pay the subscription fee later for this view.

The main program 801 is a subprogram started at first by the CPU 706when the power is turned on, and controls other subprograms.

The initialization subprogram 802 is started by the main program 801when the power is turned on, exchanges information, etc. with theterminal apparatus 500 and executes an initialization process. Detailsof the initialization process are defined in OpenCable™, HOST-PODInterface Specification (OC-SO-HOSTPOD-IF-I12-030210) and aspecification document referred by this specification document. Also, aninitialization process that is not defined in the specification is alsoexecuted. Here, a part of it is introduced. When the power is turned on,the initialization subprogram 802 notifies a first frequency memorizedin the second storage unit 705 to the QPSK demodulation unit 502 throughthe CPU 514 of the terminal apparatus 500. The QPSK demodulation unit502 executes a tuning process with the first frequency provided, andsends a signal to the second descrambler unit 702. Also, theinitialization subprogram 802 provides descramble information such as afirst key memorized in the second storage unit 705 to the seconddescrambler unit 702. As a result of it, the second descrambler unit 702executes descrambling and passes the outcome to the CPU 706 thatexecutes the initialization subprogram 802. Therefore, theinitialization subprogram 802 can receive the information. In thepresent embodiment, the initialization subprogram 802 is supposed toreceive the information via the network subprogram 803. Its detail willbe explained later.

Additionally, the initialization subprogram 802 notifies the secondfrequency memorized in the second storage unit 705 to the QPSKdemodulation unit 503 via the CPU 514 of the terminal apparatus 500. Theinitialization subprogram 802 provides scramble information memorized inthe second storage unit 705 to the scrambler unit 703. When theinformation to be sent by the initialization subprogram 802 is providedto the scrambler unit 703 via the network subprogram 803, the scramblerunit 703 scrambles the data using the scramble information provided andpasses it to the QPSK demodulation unit 503 of the terminal apparatus500. The QPSK demodulation unit 503 demodulates the scrambledinformation provided and sends it to the head end 101.

As a result of this, the initialization subprogram 802 is capable ofconducting interactive communications with the head end 101 through theterminal apparatus 500, the second descrambler unit 702, the scramblerunit 703 and the network subprogram 803.

The network subprogram 803 is a subprogram for conducting interactivecommunications with the head end 101, which is used by a plural numberof subprograms such as the main program 801 and the initializationsubprogram 802. To be more specific, it acts like having interactivecommunications with the head end 101 through TCP/IP for othersubprograms that use the network subprogram 803. TCP/IP is a well knowntechnology that stipulates a protocol for information exchanges betweena plural number of apparatuses, and its detail explanation is omittedhere. The initialization subprogram 802 is started when the power isturned on, and the network subprogram 803 notifies a MAC address (anacronym of Media Access Control address), which is an identifieridentifying POD 504 memorized by the second storage unit 705 in advance,and request to obtain the IP address. The head end 101 notifies the IPaddress to the POD 504 via the terminal apparatus 500, and the networksubprogram 803 memorizes the IP address in the first storage unit 704.From this point, the head end 101 and the POD 504 use this IP address asan identifier of the POD 504, and conducts communications.

The reproduction subprogram 804 provides descramble information such asa second key, etc., which is memorized in the second storage unit 705,and descramble information such as a third key, etc., which is providedfrom the terminal apparatus 500, to the first descrambler unit 701, andenables a descrambling process. Also, it receives via the networksubprogram 803 information that the signal entered in the firstdescrambler unit 701 is a PPV channel. When it recognizes that it is PPVchannel, it starts the PPV subprogram 805.

When the PPV subprogram 805 is started, it displays a message to promptsubscription of a program on the terminal apparatus 500, and receivesthe user's input. To be more specific, when information to be displayedon a screen is sent to the CPU 514 of the terminal apparatus 500, aprogram that activates on the CPU 514 of the terminal apparatus 500displays a message on the display 509 of the terminal apparatus 500.When the user enters a personal identification number through the inputunit 513 of the terminal apparatus 500, the CPU 514 of the terminalapparatus 500 receives it and notifies it to the PPV subprogram 815 thatactivates on the CPU 706 of the POD 504. The PPV subprogram 805 sendsthe received personal identification number to the head end 101 via thenetwork subprogram 803. When the personal identification number iscorrect, the head end 101 notifies descramble information such as afourth key, which is necessary for descramble, to the PPV subprogram viathe network subprogram 803. The PPV subprogram 805 provides the receivedthe descramble information such as the fourth key to the firstdescrambler unit 701, and the first descrambler unit 701 descrambles theentered signal.

With reference to FIG. 5, the TS decoder 505 filters the signal receivedfrom the POD 504, and provides necessary data to the audio decoder 506,the video decoder 508 and the CPU 514. The signal coming from the POD504 here is an MPEG2 transport stream. Details of the MPEG2 transportstream are described in the IOS/IEC13818-1 as an MPEG standard document,and their explanation is omitted here in the present embodiment. TheMPEG 2 transport stream is made up of a plural number of fixed lengthpackets, and a packet ID is assigned to each packet. FIG. 9 is a packetconfiguration diagram. 900 is a packet structured in a fixed length of188 bytes. The first 4 bytes are a header 901 that stores packetidentification information, and the remaining 184 bits are a payload 902that contains information to be sent. 903 is a breakdown of the header901. The packet ID is contained in 13 bits from the 12th bit to the 24thbit. FIG. 10 is a pattern diagram that expresses a plural number ofpacket columns to be sent. A packet 1001 has a packet ID “1” in itsheader and a payload contains first information of video A. A packet1002 has a packet ID “2” in its header and a payload contains firstinformation of audio A. A packet 1003 has a packet ID “3” in its headerand the payload contains first information of audio B.

A packet 1004 has a packet ID “1” in its header, a payload containssecond information of the video A, which is the subsequent informationof the packet 1001. In a similar way to this, packets 1005, 1026 and1027 contain subsequent data of other packets. In a way like this, whencontents of the packet payloads containing the same packet ID areconcatenated, continued video or audio can be reproduced.

With reference to FIG. 10, when the CPU 514 designates the packet ID “1”and a “video decoder 508” as an output destination to the TS decoder505, the TS decoder 505 extracts a packet with the packet ID “1” fromthe MPEG 2 transport stream received from the POD 504, and passes it tothe video decoder 508. In FIG. 10, only the video data is passed to thevideo decoder 508. At the same time, when the CPU 514 designates thepacket ID “2” and the “audio decoder 506” to the TS decoder 505, the TSdecoder 505 extracts a packet with the packet ID “2” from the MPEG2transport stream received from the POD 504, and passes it to the audiodecoder 506. In FIG. 10, only the audio data is passed to the audiodecoder 506.

A process to extract only a necessary packet according to this packet IDis a filtering process conducted by the IS decoder is 505. The TSdecoder 505 can executes a plural number of filtering processesdesignated from the CPU 514 at the same time.

With reference to FIG. 5, the audio decoder 506 concatenates audio dataembedded in the packets of MPEG2 transport stream provided from the TSdecoder 505, executes digital-analog conversion, and outputs it to aspeaker 507.

The speaker 507 outputs a signal provided from the audio decoder 506 asaudio.

The video decoder 508 decodes the video data, which is embedded in thepacket of the MPEG2 transport stream provided from the TS decoder 505,into a video buffer 517. Also, it reads video information such as dataresolution of the video and a ratio of height and width of the video,e.g. 4 to 3 or 16 to 9, and detects any changes in the videoinformation. The information detected is notified to a video formatresolution change detecting unit 3104, which is explained later.

A still decoder 515 decodes MPEG-I frame data, which is designated fromthe CPU 514, into a still buffer 518. Because details of the MPEG2-Iframe are described in ISO/IEC13818-2 as an MPEG standard document, itsdetailed explanation is omitted here in the present embodiment.

The OSD controlling unit 516 decodes graphics data, which is designatedfrom the CPU 514, into an OSD buffer 519.

According to an enlargement and reduction command designated from theCPU 514, the video enlargement and reduction unit 520 enlarges orreduces the data stored in the video buffer 517, and passes it to acomposing unit 523.

According to an enlargement and reduction command designated from theCPU 514, the still enlargement and reduction unit 521 enlarges orreduces the data stored in the video buffer 518, and passes it to thecomposing unit 523.

According to an enlargement and reduction command designated from theCPU 514, the OSD enlargement and reduction unit 522 enlarges or reducesthe data stored in the video buffer 519, and passes it to the composingunit 523.

The composing unit 523 follows a Z order of each plane designated fromthe CPU 514, and superposes the data passed from the video enlargementand reduction unit 520, the data passed from the still enlargement andreduction unit 521 and the data passed from the OSD enlargement andreduction unit 522, and outputs it to the display 509. In order toexplain the Z order of each plane designated from the CPU 514, a generalTV receiver has three layered structure, which has an OSD planedisplaying characters and graphics, a video plane displaying a video,and a still plane displaying a still image, and its order of thesuperposition is called as Z order. For example, with reference to FIG.22, if 2201 is a first plane viewed at a front side from a viewer, 2202is a second plane that is located at a back side of 2201, and 2203 is athird plane that is located at the furthest back, there are six possiblecombinations as described in FIG. 23.

The display 509 is, to be more specific, made up of a cathode-ray tube,a liquid crystal display, etc., which outputs a video signal providedfrom the video decoder 508, and displays a message designated from theCPU 514.

The secondary memory 510, to be more specific, is made up of a flashmemory, hard disk, etc., which stores and deletes data or programsdesignated from the CPU 514. Also, the data and the programs stored arereferred to by the CPU 514. The data and the programs stored remain tobe stored even if the power of the terminal apparatus 500 is turned off.

The primary storage unit 511 is, to be more specific, made up of RAM,etc., which temporarily stores and deletes data and programs designatedby the CPU 514. Additionally, the data and the programs stored arereferred by the CPU 514. The data and the programs stored are clearedwhen the power of the terminal apparatus 500 is turned off.

ROM 512 is a memory device that cannot be rewritten, which is, to bemore specific, made up of ROM, CD-ROM, DVD, etc. The ROM 512 stores aprogram executed by the CPU 514.

The input unit 513 is, to be more specific, made up of a front panel anda remote controller, which accepts an input from the user. FIG. 11 is anexample for a case that the input unit 513 is made up of the frontpanel. 1100 is a front panel, which is equivalent to the front panel 603in FIG. 6. The front panel 1100 includes 7 buttons, an up cursor button1101, a down cursor button 1102, a left cursor button 1103, a rightcursor button 1104, an OK button 1105, a cancel button 1106 and an EPGbutton 1107. When the user presses one of the buttons, an identifier ofthe pressed button is notified to the CPU 514.

The CPU 514 executes a program memorized in the ROM 512. According tothe program executed, the CPU 514 controls the QAM demodulation unit501, the QPSK demodulation unit 502, the QPSK modulation unit 503, thePOD 504, the TS decoder 505, the display 509, the secondary storage unit510, the primary storage unit 511 and the ROM 512.

FIG. 12 is an example of a configuration diagram for the programmemorized in the ROM 512 and executed by the CPU 514.

A program 1200 is made up of a plural number of subprograms, which is,to be more specific, made up of an OS 1201, an EPG 1202, a Java VM 1203,a service manager 1204 and a Java library 1205.

The OS 1201 is a subprogram that is started by the CPU 514 when thepower of the terminal apparatus 500 is turned on. The OS 1201 is anabbreviation of Operation System, and its example is Linux, etc. The OS1201 is a generic name for a publicly well-known technology made up of akernel 1201 a, which concurrently executes other subprograms, and alibrary 1201 b, and its detailed explanation is omitted here. In thepresent embodiment, the kernel 1201 a of the OS 1201 executes the EPG1202 and the Java VM 1203 as a subprogram. Also, the library 1201 bprovides a plural number of functions for controlling structuralelements held by the terminal apparatus 500 for these subprograms.

As one of the functions, a tuning function is introduced here. With thetuning function, tuning information that includes a frequency isreceived from other subprograms, and passed to the QAM demodulation unit501. Accordingly, it becomes possible for the QAM demodulation unit 501to execute a demodulation process based on the provided tuninginformation, and to pass the demodulated data to the POD 504. As aresult of this, other subprogram can control the QAM demodulator via thelibrary 1201 b.

The EPG is made up of a program display unit 1202 a that displays a listof programs to the user and accepts an input from the user, and areproduction unit 1202 b that select a channel. The EPG stated here isan acronym of Electric Program Guide.

When the power of the terminal apparatus 500 is turned on, the EPG 1202is started by the kernel 1201 a. Within the EPG 1202 started, theprogram display unit 1202 a waits for an input from the user via theinput unit 513 of the terminal apparatus 500. When the input unit 513 ismade up of a front panel indicated in FIG. 11 and the user presses theEPG button 1107 of the input unit 513, an identifier of the EPG buttonis notified to the CPU 514. The program display unit 1202 a of the EPG1202, which is a subprogram activated on the CPU 514, receives thisidentifier, and displays program information on the display 509. FIG.13(1) and FIG. 13(2) are examples of program charts displayed on the isdisplay 509. With reference to FIG. 13(1), the display 509 displays theprogram information in a grid pattern. Time schedule information isdisplayed in a column 1301. A channel name “Channel 1” and a programshown in a time zone corresponding to the time schedule in the column1301 are displayed in a column 1302. It shows that a program called“News 9” is televised from 9:00 to 10:30 and a program called “MovieAAA” is televised from 10:30 to 12:00 on the “Channel 1”. In the sameway as the column 1302, a channel name “Channel 2” and a program shownin a time zone corresponding to the time schedule in the column 1301 areshown in a column 1303. It shows that a program called “Movie BBB” istelevised from 9:00 to 11:00 and a program called “News 11” is televisedfrom 11:00 to 12:00. 1330 is a cursor. The cursor 1330 is moved bypressing the left cursor 1103 and the right cursor 1104 on the frontpanel 1100. In a situation of FIG. 13(1), the cursor 1330 is moved to aright side when the right cursor 1104 is pressed down, which is as shownin FIG. 13(2). Also, in a situation of FIG. 13(2), the cursor 1330 ismoved to a left side when the left cursor 1103 is pressed down, which isas shown in FIG. 13(1).

In a situation of FIG. 13(1), when an OK button 1105 of the front panel1100 is pressed down, the program display unit 1202 a notifies anidentifier of the “Channel 1” to the reproduction unit 1202 b. In asituation of FIG. 13(2), when the OK button 1105 of the front panel 1100is pressed down, the program display unit 1202 a notifies an identifierof the “Channel 2” to the reproduction unit 1202 b.

Also, the program display unit 1202 a memorizes the displaying programinformation in the primary storage unit 511 from the head end 101 on aregular basis via the POD 504. Generally speaking, acquirement of theprogram information from the head end takes time. When the EPG button1107 of the input unit 513 is pressed down, a program chart can bequickly displayed by displaying the program information pre-stored inthe primary storage unit 511.

The reproduction unit 1202 b reproduces a channel using the receivedidentifier of the channel. Relationship between the channel identifierand the channel is pre-stored in the secondary storage unit 510 aschannel information. FIG. 14 is an example of channel information storedin the secondary storage unit 510. The channel information is stored ina tabular form. A column 1401 is a channel identifier. A column 1402 isa channel name. A column 1403 is tuning information. The tuninginformation here includes frequencies, transmission rates, coding rates,etc., which are values provided to the QAM demodulation unit 501. Acolumn 1404 is a program number. The program number here is a numberthat identifies PMT stipulated in the MPEG2 standard. PMT will beexplained later. Each line from the line 1411 to the line 1414 is a setof each channel identifier, channel name and tuning information. Theline 1411 is a set that includes “1” as the identifier, “Channel 1” asthe channel name, a frequency “150 MHz” for the tuning information and“101” as the program number. For reproducing the channel, thereproduction unit 1202 b passes the received channel identifier to theservice manager as it is.

Also, when the user presses down the up cursor 1101 and the down cursor1102 during reproduction, the reproduction unit 1202 b receives thepressed notification via the CPU 514 from the input unit 513 and changesthe channel being reproduced. At first, the reproduction unit 1202 bmemorizes, in the primary storage unit 511, an identifier of the channelcurrently being reproduced. FIG. 15(1), FIG. 15(1) and FIG. 15(3) areexamples of identifiers of channels stored in the primary storage unit511. FIG. 15(1) shows an identifier “3” is memorized, and with referenceto FIG. 14, it shows that a channel of a channel name called “TV 3” isbeing reproduced. In a situation of FIG. 15(1), when the user pressesdown the up cursor 1101, the reproduction unit 1202 b refers to thechannel information of FIG. 14 and passes an identifier “2” of a channelname “Channel 2” to the service manager for switching the channel toreproduce a channel name called “Channel 2”, which is a previous channelin the chart. At the same time, the channel identifier “2” memorized inthe primary storage unit 511 is rewritten. FIG. 15(2) shows a situationthat the channel identifier is rewritten. Also, in a state of FIG.15(1), when the user presses down the down cursor 1102, the reproductionunit 1202 b refers to channel information in FIG. 14, and passes anidentifier “4” of a channel name called “TV Japan” to the service managefor switching the channel to reproduce the channel name called “TVJapan”, which is a next channel in the chart. At the same time, thechannel identifier “4” memorized in the primary storage unit 511 isrewritten. FIG. 15(3) shows a state when the channel identifier isrewritten.

Java VM 1203 is a Java virtual machine that consecutively analyzes andexecutes a program described in a Java™ language. The program describedin the Java language is compiled into intermediate codes called as bytecodes, which are not depended on hardware. The Java virtual machine isan interpreter that executes these byte codes. Also, a part of the Javavirtual machine translates the byte codes into an execution format,which is comprehensive to the CPU 514, and passes it to the CPU 514,which executes it. Java VM 1203 is started when the kernel 1201 aspecifies the Java program to be executed. In the present embodiment,the kernel 1201 a specifies the service manager 1204 as a Java programto be executed. Details of the Java language are described in many bookssuch as a book called “Java Language Specification (ISBN0-201-63451-1)”. Its details are omitted here. Also, detailed actionstaken by Java VM itself are described in many books such as a bookcalled “Java Virtual Machine Specification (ISBN 0-201-63451-X)”. Itsdetails are omitted here.

The service manager 1204 is a Java program written in the Java language,and consecutively executed by the Java VM 1203. It is possible for theservice manager 1204 to call up or to be called by other subprogramsthat are not described in the Java language, via JNI (Java NativeInterface). JNI is also described in many books such as a book called“Java Native Interface”. Its details are omitted here.

The service manager 1204 receives a channel identifier from thereproduction unit 1202 b via the JNI.

The service manager 1204 at first passes the channel identifier to atuner 1205 c located in the Java library 1205 and requests for tuning.The tuner 1205 c refers to channel information memorized in thesecondary storage unit 510 and acquires tuning information. Now, whenthe service manager 1204 passes a channel identifier “2” to the tuner1205 c, the tuner 1205 c refers to a line 1412 in FIG. 14, and acquirescorresponding tuning information “156 MHz”. The tuner 1205 c passes thetuning information to the QAM demodulation unit 501 via the library 1201b of the OS 1201. According to the provided tuning information, the QAMdemodulation unit 501 demodulates a signal sent from the head end 101,and passes it to the POD 504.

Next, the service manager 1204 requests descrambling to CA 1205 d in thelava library 1205. The CA 1205 d provides information necessary fordescramble to the POD 504 via the library 1201 b of OS 1201. Based onthe information provided, the POD 504 descrambles the signal providedfrom the QAM demodulation unit 501 and passes it to the TS decoder 505.

Next, the service manager 1204 provides an identifier of the channel toJMF 1205 a in the lava library 1205, and requests reproduction of videoand audio.

At first, the JMF 1205 a acquires a packet ID from PAT and PMT forspecifying the video and the audio to be reproduced. PAT and PMT aretables describing program structure in the MPEG2 transport stream, whichis stipulated in the MPEG2 standards. They are embedded in the payloadof the packet included in the MPEG2 transport stream, and sent with theaudio and the video. Please see the standard manual for its details.Only the outline is explained here. PAT is an acronym of ProgramAssociation Table, stored in the packet of the packet ID “0” and sent.To acquire PAT, the JMF 1205 a designates the packet ID “0” and the CPU514 to the TS decoder 505 via the library 1201 b of OS1201. The JMF 1205a collects packets of PAT by having the TS decoder 505 execute afiltering process with the packet ID “0” and pass it to the CPU 514.FIG. 16 is a table describing a typical example of PAT informationcollected. A column 1601 is a program number. A column 1602 is a packetID. The packet ID in the column 1602 is used to acquire PMT. Lines 1611to 1613 are a set of a program number of the channel and itscorresponding packet ID. three channels are defined here in this table.A set of a program number “101” and a packet ID “501” is defined in aline 1611. Suppose the channel identifier provided to the IMF 1205 a is“2”, the IMF 1205 a acquires “102” as its corresponding program numberwith reference to a line 1412 in FIG. 14, and then acquires a packet ID“502” corresponding to the program number “102” with reference to theline 1612 in the PAT described in FIG. 14. The PMT is an abbreviation ofProgram Map Table, which is stored in the packet of the packet IDstipulated by the PAT and sent. To acquire the PMT, the JMF 1205 adesignates the packet ID and the CPU 514 to the TS decoder 505 via thelibrary 1201 b of OS 1201. Suppose the packet ID designated here is“502”. The JMF 1205 a collects packets of PMT by having the TS decoder505 execute a filtering process with the packet ID “502” and pass it tothe CPU 514. FIG. 17 is a table describing a typical example of PMTinformation collected. A column 1701 is a stream type, and a column 1702is a packet ID. In a packet of the packet ID designated by the column1702, information designated by the stream type is stored in a payloadand sent. A column 1703 is supplemental information. Columns 1711 to1714 are a set of a packet ID called as an elementary stream and a typeof information being sent. The column 1711 is a set of a stream type“audio” and a packet ID “5011”, which shows that audio is stored in apayload of the packet ID “5011”. The IMF 1205 a acquires packet IDs ofvideo and audio reproduced from the PMT. With reference to FIG. 17, theIMF 1205 a acquires a packet ID “5011” for audio from the line 1711, anda packet ID “5012” for video from the line 1712.

Next, the IMF 1205 a provides a set of the acquired audio packet ID andan audio decoder 506 as its output destination and the acquired videopacket ID and a video decoder 508 as its output destination to the TSdecoder 505 via the library 1201 b of the OS 1201. The TS decoder 505executes a filtering process based on the provided packet IDs and theiroutput destinations. Here, the packet of the packet ID “5011” isprovided to the audio decoder 506, and the packet of the packet ID“5012” is provided to the video decoder 508. The audio decoder 506executes digital-analogue conversion for the packet provided, andreproduces the audio via a speaker 507. The video decoder 508 decodesthe video data, which is embedded in the packet of the MPEG2 transportstream provided from the TS decoder 505, into a video buffer 517.

According to an enlargement and reduction command directed from the CPU514, the video-enlargement and reduction unit 520 enlarges or reducesthe data stored in the video buffer 517 and passes it to the composingunit 523.

According to the Z order directed from the CPU 514, the composing unit523 superposes the data provided from the video enlargement andreduction unit 520, the data provided from the still enlargement andreduction unit 521, and the data provided from the OSD enlargement andreduction unit 522, and outputs it to the display 509.

Finally, the service manager 1204 provides a channel identifier to theAM 1205 b located in the Java library 1205, and requests databroadcasting reproduction. The data broadcasting reproduction here meansto extract a Java program contained in the MPEG2 transport stream and tohave the JavaVM 1203 execute the program. Regarding a method to embed aJava program into the MPEG2 transport stream, a method called as DSMCCdescribed in an MPEG standard document ISO/IEC 13818-6 is used. Itsdetailed explanation for DSMCC is omitted here. The DSMCC methodstipulates a method for encoding a file system, which is made up of adirectory and a file used in a computer, into a packet of the MPEG2transport stream. Also, the information of the Java program executed ina style called AIT is embedded into the packet of the MPEG2 transportstream and sent. The AIT is an abbreviation of Application InformationTable, which is defined in Chapter 10 of DVB-MHP standard (formally,ETSI TS 101 812 DVB-MHP specifications V1.0.2).

The AM 1205 b at first acquires the PAT and the PMT in the same way asthe JMF 1205 a for acquiring the AIT, and then acquires the packet ID ofthe packet where the AIT is stored. Suppose an identifier of theprovided channel is “2” now, and the PAT in FIG. 16 and the PMT in FIG.17 are sent, it acquires the PMT in FIG. 17 in the same procedures asthe one for the JMF 1205 a. The AM 1205 b extracts a packet ID, whichhas “data” as its stream type and “AIT” as its supplemental information,from the elementary stream. With reference to FIG. 17, the AM 1205 bacquires the packet ID “5013” since the elementary stream in the line1713 is applicable.

The AM 1205 b provides the packet ID of the AIT and the CPU 514 as itsoutput destination to the TS decoder 505 via the library 1201 b of theOS 1201. A filtering process is executed with the TS decoder 505 and theprovided packet ID, and a processed outcome is passed to the CPU 514. Asa result of this, the AM1205 b can collect the packet of the AIT. FIG.18 is a table, which describes a typical example of the AIT informationcollected. A column 1801 is an identifier of the Java program. A column1802 is control information of the Java program. There are “autostart”,“present”, “kill”, etc. as the control information. The “autostart”means that a terminal apparatus 500 automatically and immediatelyexecutes this program, the “present” means that the terminal apparatus500 does not automatically execute the program, and the “kill” meansthat the terminal apparatus 500 stops the program. A column 1803 is aDSMCC identifier for extraction a packet ID containing the Java programin a DSMCC method. A column 1804 is a program name of the Java program.The lines 1811 and 1812 are a set of the Java program information. TheJava program defined in the line 1811 is a set of an identifier “301”,control information “autostart”, a DSMCC identifier “1”, and a programname “a/TopXlet”. The Java program defined in the line 1812 is a set ofan identifier “302”, control information “present”, a DSMCC identifier“1”, and a program name “b/GameXlet”. These Java programs here containthe same DSMCC identifier. It means that two Java programs are containedin a file system that is encoded in one DSMCC method. Although only fourtypes of information are stipulated for the Java program here, therewill be more information defined in practice. Please see DVB-MHPstandards for details.

The AM 1205 b finds out the Java program of “autostart” within the AIT,and extracts its corresponding DSMCC identifier and Java program name.With reference to FIG. 18, the AM 1205 b extracts the Java program inthe line 1811, and acquires the DSMCC identifier “1” and the Javaprogram name “a/TopXlet”.

Next, the AM 1205 b acquires the packet ID of the packet, which storesthe Java program in the DSMCC method, from the PMT using the DSMCCidentifier acquired from the AIT. To be more specific, the AM 1205 bacquires the packet ID of the elementary stream, which has “data” as itsstream type and a matching DSMCC identifier in the supplementalinformation.

Suppose that the DSMCC identifier is now “1”, and the PMT is just asdescribed in FIG. 17, the elementary stream in a line 1714 is matchedwith the condition so that the packet ID “5014” is extracted.

The AM 1205 b designates a packet ID of the packet, where data isembedded into the TD decoder 505 in the DSMCC method, and the CPU 514 asits output destination via the library 1201 b of the OS 1201. The packetID “5014” is provided here. A filtering process is executed with the TSdecoder 505 and the provided packet ID and its processed outcome ispassed to the CPU 514. As a result of this, the AM 1205 b can collectnecessary packets. The AM 1205 b restores a file system according to theDSMCC method from the collected packets, and stores it in the primarystorage unit 511. Hereinafter, actions to take out the data such as filesystems from the packet in the MPEG2 transport stream and to store it ina memorizing mean such as the primary storage unit 511 are referred toas “download”.

FIG. 19 is an example of a file system downloaded. In the figure, acircle indicates a directory, a square indicates a file, 1901 is a rootdirectory, 1902 is a directory “a”, 1903 is a directory “b”, 1904 is afile “TopXlet.class”, and 1905 is a file “GameXlet.class”.

Next, the AM 1205 b passes the Java program executed from the filesystem downloaded to the primary storage unit 511 to the JavaVM 1203.Suppose the Java program name executed now is “a/TopXlet”, a file“a/TopXlet.class” where “.class” is added to an end of the Java programname is the file to be executed. “/” is a delimiter of a directoryand/or a file name, which is the Java program that should be executed bythe file 1904 with reference to FIG. 19. Next, the AM 1205 b providesthe file 1904 to the Java VM 1203.

The Java VM 1203 executes the provided Java program.

Once the service manager 1204 receives an identifier of another channel,it stops execution of the Java program and video and audio, which arebeing reproduced through each library contained in the Java library1205, and via each library contained in the same Java library 1205,conducts the Java program and reproduced video and audio based on thenewly received channel identifier.

The Java library 1205 is a set of a plural number of Java librariesstored in a ROM 512. In the present embodiment, the Java library 1205here contains JMF 1205 a, AM 1205 b, Tuner 1205 c, CA 1205 d, POD Lib1205 e, a resolution switching unit 1205 f, AWT 1205 g, STL 1205 h, etc.

The POD Lib 1205 e provides functions to acquire information from thePOD 504 and to control the POD 504 via the library 1201 b and the CPU514.

The resolution switching unit 1205 f provides a function to control thevideo decoder 508, the video enlargement and reduction unit 520, thestill decoder 515, the still enlargement and reduction unit 521, the OSDenlargement and reduction unit 516, and the OSD enlargement andreduction unit 522 through the CPU 514. Details are described later.

The AWT 1205 g accepts a rendering instruction from the Java program.Based on the accepted instruction, the AWT 1205 g draws characters andgraphics in the OSD buffer by sending necessary information to the OSDcontrolling unit 516. As a specific example for a rendering process,there is a process for rendering a line or rendering a square, which isa publicly known technology realized in a class and interfacespecifications stipulated in a Java.awt package. Therefore, its detailedexplanation is omitted here.

The STL 1205 h accepts MPEG-I frame data displayed from the Java programand its display position. The STL 1205 h passes the accepted MPEG-Iframe data and its display position to the still decoder 515. The stilldecoder 515 decodes the MPEG-I frame data to the provided displayposition, and stores it into the still buffer 518. By doing so, the Javaprogram can draw pictures in the still buffer.

FIG. 24 is a flowchart related to a video display process. The TSdecoder 505 transfers video data to the video decoder 508 (S2401). Thevideo decoder 508 decodes the transferred video data, and stores itsoutcome into the video buffer 517 (S2402). The video decoder 508 decideswhether there is an instruction of enlargement and reduction regardingthe video display from the CPU 514 or not (S2403). If there is theinstruction of enlargement and reduction, the video enlargement andreduction unit 520 executes the enlargement and reduction process to thedata being stored in the video buffer 517 (S2404), and transfers it tothe composing unit 523 (S2405). If there is no instruction ofenlargement and reduction, the video enlargement and reduction unit 520transfers the data being stored in the video buffer 517 to the composingunit 523 (S2405).

FIG. 25 is a flowchart related to a still display process. MPEG2-I framedata is provided from the CPU 514 to the still decoder 515 (S2501). Thestill decoder 515 decodes the provided MPEG2-I frame data, and storesthe outcome into the still buffer 518 (S2502). The still decoder 515decides whether there is an instruction of enlargement and reductionregarding the still display from the CPU 514 (S2503). When there is theinstruction of enlargement and reduction, the still enlargement andreduction unit 521 executes the enlargement and reduction process to thedata being stored in the still buffer 518 (S2504), and it transfers itto the composing unit 523 (S2505). When there is no instruction ofenlargement and reduction, the still enlargement and reduction unit 521transfers the data being stored in the still buffer 518 to the composingunit 523.

FIG. 26 is a flowchart related to the display process of OSD. Characterand graphics data is provided from the CPU 514 to the OSD controllingunit 516 (S2601). The OSD controlling unit 516 builds up the video inthe OSD buffer 519 based on the provided characters and graphics data(S2602). The OSD controlling unit 516 decides whether there is aninstruction of enlargement and reduction related to the display of OSDfrom the CPU 514 (S2603). If there is the instruction of enlargement andreduction, the OSD enlargement and reduction unit 522 executes theenlargement and reduction process to the data being stored in the OSDbuffer 519 (S2604), and transfers it to the composing unit 523 (S2605).If there is no instruction of enlargement and reduction, the OSDenlargement and reduction unit 522 transfers the data being stored inthe OSD buffer 519 to the composing unit 523.

Here, the video of enlargement and reduction is explained with referenceof an example. Like 2801 of FIG. 28, when data of 720 pixels in widthand 480 pixels in height is enlarged in size, i.e. enlarged to 960pixels in width and 540 pixels in height, it becomes just as shown in2802 of FIG. 28.

FIG. 27 is a flowchart related to a composing process for a videogenerated in the flowchart shown in FIG. 24, a still generated in theflowchart shown in FIG. 25 and an OSD generated in the flowchart shownin FIG. 26. The composing unit 523 decides whether there is a changeinstruction of Z order from the CPU 514 (S2701) or not. If there is thechange instruction, it decides which of planes, a video plane, a stillplane or an OSD plane is applicable to a first plane 2201, a secondplane 2202 and a third plane 2203 according to the change instruction(S2702). Here, the video plane means to be a video generated through theflowchart shown in FIG. 24, the still plane means to be a stillgenerated through the flowchart shown in FIG. 25, and the OSD planemeans to be an OSD generated through the flowchart shown in FIG. 26. Ifthere is no change instruction, the previous Z order is followed. Acombination of the Z order is one of fix pattern combinations asindicated in FIG. 23. Next, the composing unit 523 decides which of theplanes, the video plane, the still plane or the OSD plane is applicableto the plane relevant to the third plane, which is located at thefurthest back (S2703). When the plane is the video plane, video data iscomposed in the composing unit 523 (S2704). When the plane is the stillplane, still data is composed in the composing unit 523 (S2705). Whenthe plane is the OSD plane, OSD data is composed in the composing unit523 (S2706). For example, for a case that the video of composed data is2901 of FIG. 29, the video after the composing process is just as 3001of FIG. 30. Next, the composing unit 523 decides which of the planes,the video plane, the still plane or the OSD plane is applicable to theplane relevant to the second plane (S2707). When the plane is the videoplane, video data is composed in the composing unit 523 (S2708). Whenthe plane is the still plane, still data is composed in the composingunit 523 (S2709). When the plane is the OSD plane, OSD data is composedin the composing unit 523 (S2710). For example, when the video of thecomposed data is 2902 of FIG. 29, the video after the composing processis just as shown in 3002 of FIG. 30.

Next, the composing unit 523 decides which of the planes, the videoplane, the still plane or the OSD plane is applicable to the planerelevant to the first buffer, which is located at the foreground(S2711). When the plane is the video plane, video data is composed inthe composing unit 523 (S2712). When the plane is the still plane, stilldata is composed in the composing unit 523 (S2713). When the plane isthe OSD plane, OSD data is composed in the composing unit 523 (S2714).For example, for a case that the video of composed data is 2903 of FIG.29, the video after the composing process is just as shown in 3003 ofFIG. 30. Finally, a result of the composing process is output anddisplayed on the display 509 (S2715).

The following explains downloading and saving the lava program as wellas display actions of the Java program.

The service manager 1204 conducts interactive communications with thehead end 101 through the POD Lib1205 e contained in the Java library1205. This interactive communication is realized by using the QPSKdemodulation unit 502 and the QPSK modulation unit 503 via the library1201 b and the POD 504 of the OS 1201.

The service manager 1204 receives Java program information, which shouldbe saved by the terminal apparatus 500 in the secondary storage unit510, from the head end 101 by using this communication. This informationcalled as XAIT information. The XAIT information is sent in adiscretional form between the head end 101 and the POD 504. Whatever thesending form is chosen, the present invention is executable as long asthe information necessary for the XAIT is contained.

FIG. 20 is a chart describing a typical example of the XAIT informationobtained from the head end 101. A column 2001 is a Java programidentifier. A column 2002 is control information of the Java program.There is “autoselect”, “present” and so on as the control information,and “autoselect” means to execute this program automatically when theterminal apparatus 500 is powered on, and “present” means not to executethis program. A column 2003 is a DSMCC identifier for extracting apacket ID containing the Java program in the DSMCC method. A column 2004is a program name of the Java program. A column 2005 is a priority ofthe Java program. Lines 2011 and 2012 are a set of Java programinformation. The Java program defined in the line 2011 is a set of theidentifier “701”, the control information “autoselect”, the DSMCCidentifier “1”, the program name “a/Banner1Xlet”. Here, there are fivetypes of information stipulated for the Java program. However, thepresent invention is executable even if more information is defined.

When the service manager 1204 receives the XAIT information, it saves afile system in the primary storage unit 511 from the MPEG2 transportstream in the same procedure as the procedure to download the lavaprogram from the AIT information. And then, the file system saved iscopied to the secondary storage unit 510. However, it is also possibleto download the file system directly to the secondary storage unit 510without having the process done through the primary storage unit 511.Next, the service manager 1204 saves XAIT information in the secondarystorage unit 510 by linking it to a storage location of the downloadedfile system. FIG. 21 shows an example of how the XAIT information andthe downloaded file system are linked and saved in the secondary storageunit 510. Explanation for elements in FIG. 21 having the same number asthose elements in FIG. 20 is omitted here. A column 2101 stores a savinglocation of the corresponding file system downloaded. In the diagram,the saving location is indicated with a column. 2110 is the downloadedfile system, which internally holds a top directory 2111, a directory“a” 2112, a directory “b” 2113, a file “Banner1Xlet.class” 2114 and afile “Banner2Xlet.class” 2115.

Here, the XAIT information is saved after the lava program is saved.However, the XAIT information may be saved before the Java program issaved.

After the terminal 500 is turned on, the OS 1201 designates the servicemanager 1204 to the lavaVM 1203. After the JavaVM 1203 activates theservice manager 1204, the service manager 1204 at first refers to theXAIT information saved in the secondary storage unit 510. Here, theservice manager 1204 refers to the control information of each Javaprogram, provides the program of “autoselect” to the JavaVM 1203 andactivates it. With reference to FIG. 21, the lava program “Banner1Xlet”defined in the line 2011 is activated.

Once the Java program “Banner1Xlet” is activated, the Java program“Banner1Xlet” designates to display an OSD to the CPU 514 when the Javaprogram “Banner1Xlet” displays characters and graphics. The CPU 514provides the characters and the graphics to the OSD controlling unit516, and the OSD display process is executed, and finally an OSD planeis composed with a video plane and a still plane and displayed on thedisplay 509.

Next, the following describes a video resolution switching function,which is the main function of the present invention. FIG. 31 is aconfiguration diagram of the video resolution switching function.

An application program 3100 is, for example, an application such as aJava program called “Banner1Xlet”.

A resolution switching unit 1205 f contains an OSD resolution managingunit 3101, a video resolution managing unit 3102, a still resolutionmanaging unit 3103, a video format resolution change detecting unit 3104and a resolution selection deciding unit 3105, and serves as a videoresolution switching function.

The OSD resolution managing unit 3101 manages resolution of an OSDplane. The OSD resolution managing unit 3101 has a function to accept achange request of the current OSD plane resolution from the applicationprogram 3100, and a function to notify a change in the resolution of theOSD plane to the application program 3100. When the change request ofthe OSD plane resolution is accepted, the OSD resolution managing unit3101 notifies it to the resolution selection deciding unit 3105.

The video resolution managing unit 3102 manages resolution of a videoplane. The video resolution managing unit 3102 has a function to accepta change request of the current video plane resolution from theapplication program 3100, and a function to notify a change in theresolution of the video plane to the application program 3100. When thechange request of the video plane resolution is accepted, the videoresolution managing unit 3102 notifies it to the resolution selectiondeciding unit 3105.

The still resolution managing unit 3103 manages resolution of a stillplane. The still resolution managing unit 3103 has a function to accepta change request of the current still plane resolution from theapplication program 3100, and a function to notify a change in theresolution of the still plane to the application program 3100. When thechange request of the still plane resolution is accepted, the stillresolution managing unit 3103 notifies it to the resolution selectingunit 3105.

When the resolution of the video format received by the video decoder508 is different from the resolution of the video format previouslydecoded, the video format resolution change detecting unit 3104 notifiesit to the resolution selection deciding unit 3105.

The resolution selection deciding unit 3105 selects resolution of eachplane considering a combination of planes that can be displayed on theTV receiver when one of the following cases occurs: a case there is achange request for the current resolution of the OSD plane to the OSDresolution managing unit 3101; a case there is a change request for thecurrent resolution of the video plane to the video resolution managingunit 3102; a case there is a change request for the current resolutionof the still plane to the still resolution managing unit 3103; or a casethere is a change request of the resolution of the video format from thevideo format resolution change detecting unit 310. The followingexplains the combinations that can be displayed. The TV receiver is inthree layered structure, i.e. an OSD plane that displays characters andgraphics, a video plane that displays videos, and a still plane thatdisplays still images, and there are displayable combinations of theseplanes. For example, combinations such as those described in FIG. 32 areavailable. While the TV receiver displays each of the planes in acombination of 1 (3201) indicated in FIG. 32, the video resolution ofthe video format received by the video decoder 508 may be changed to 960pixels in width and 540 pixels in height and the screen ratio of thatmay be changed to 16:9. If that is the case, the resolution of eachplane may be changed to a combination 3 (3203) according to the videoformat. The combinations of each plane indicated in this FIG. 32 arememorized in the secondary storage unit 510, the primary storage unit511 or the ROM 512. Suppose that the combinations of each plane are nowstored in the ROM 512, it means that the resolution selection decidingunit 3105 refers to the ROM 512 when considering the best combination tobe displayed, and selects the most optimum combination according to aspecific set of rules from the available combinations.

FIG. 33 is a flowchart of the resolution selection deciding unit 3105for a case that there is a resolution change request of the current OSDplane to the OSD resolution managing unit 3101. The OSD resolutionmanaging unit 3101 provides the OSD resolution to the resolutionselection deciding unit 3105 and makes the change request (S3301). Theresolution selection deciding unit 3105 memorizes the requested OSDresolution in the primary storage unit 511 (S3302). The resolutionselection deciding unit 3105 tries to select a combination possible tobe displayed according to the requested OSD resolution (S3303). As aresult of it, the resolution selection deciding unit 3105 decideswhether it can be changed to the requested OSD resolution or not(S3304), and conducts an OSD resolution change notification to the OSDresolution managing unit 3101 if it is changed (S3305). In accordancewith this OSD resolution change, the resolution selection deciding unit3105 also decides whether the video resolution is changed or not(S3306), and conducts a video resolution change notification to thevideo resolution managing unit 3102 if it is changed (S3307). Inaccordance with this OSD resolution change, the resolution selectiondeciding unit 3105 also decides whether the still resolution is changedor not (S3308), and conducts a still resolution change notification tothe video resolution managing unit 3103 if it is changed (S3309).

FIG. 34 is a flowchart of the resolution selection deciding unit 3105for a case there is a resolution change request of the current videoplane to the video resolution managing unit 3102. The video resolutionmanaging unit 3102 provides the video resolution to the resolutionselection deciding unit 3105 and makes the change request (S3401). Theresolution selecting deciding unit 3105 memorizes the requested videoresolution in the primary storage unit 511 (S3402). The resolutionselecting deciding unit 3105 tries to select a combination possible tobe displayed according to the requested video resolution (S3403). As aresult, the resolution selecting deciding unit 3105 decides whether itcan be changed to the requested video resolution or not (S3404), andconducts a video resolution change notification to the video resolutionmanaging unit 3102 if it is changed (S3405). In accordance with thisvideo resolution change, the resolution selecting deciding unit 3105also decides whether the OSD resolution is changed or not (S3406), andconducts an OSD resolution change notification to the OSD resolutionmanaging unit 3101 if the resolution is changed (S3407). In accordancewith this video resolution change, the resolution selecting decidingunit 3105 also decides whether the still resolution is changed or not(S3408), and conducts a still resolution change notification to thestill resolution managing unit 3103 if the resolution is changed(S3409).

Here, when the selected video plane resolution is different from theresolution of the video decoded by the video decoder 508, the videoenlargement and reduction unit 520 realizes the selected video planeresolution by enlargement or reduction the video stored in the videobuffer 517 to the selected video plane resolution.

Also, displayable combinations of resolutions for a video plane, a stillplane and an OSD plane include combinations assuming enlargement andreduction of the video plane, the still plane and the OSD plane. Forexample, when the combination is “4”, i.e.3204 in FIG. 32, the OSD planeresolution is 960*540, and the video plane and the OSD plane resolutionsare respectively 1920*1080. In this case, the composing unit 523 cancompose three planes by having the OSD enlargement and reduction unit522 enlarge characters and graphics rendering stored in the OSD buffer519 to horizontally and vertically twice as big as its original size. Inthe way like this, the displayable combinations of resolutions for thevideo plane, the still plane and the OSD plane contain enlargement andreduction information that stipulates actions of the video enlargementand reduction unit 520, the still enlargement and reduction unit 521 andthe OSD enlargement and reduction unit 522. Or, the enlargement andreduction information may be memorized clearly in the secondary storageunit 510, the primary storage unit 511, the ROM 512, etc. bycorresponding the information to the displayable combinations ofresolutions for the video plane, the still plane, and the OSD plane. Theenlargement and reduction information may be specifically definedrespectively for each the video enlargement and reduction unit 520, thestill enlargement and reduction unit 521 and the OSD enlargement andreduction unit 522. Or, it may be stipulated as common resolution thatshould be output to the composing unit 523 by the video enlargement andreduction unit 520, the still enlargement and reduction unit 521 and theOSD enlargement and reduction unit 522. Also, by adding a commonresolution designating unit that designates this common resolution, theresolution of the video, the OSD and the still, which are output to thecomposing unit 523, may be easily changed. For the common resolutiondesignating unit here, the resolution may be designated by anapplication program or designated by the resolution selection decidingunit 3105.

Also, the resolution selection deciding unit 3105 directs enlargementand reduction to the video enlargement and reduction unit 520, the stillenlargement and reduction unit 521 and the OSD enlargement and reductionunit 522.

FIG. 35 is a flowchart of the resolution selection deciding unit 3105for a case there is a change request for the current still planeresolution to the still resolution managing unit 3103. The stillresolution managing unit 3103 provides the still resolution to theresolution selection deciding unit 3105 and makes the change request(S3501). The resolution selecting deciding unit 3105 memorizes therequested still resolution in the primary storage unit 511 (S3502). Theresolution selecting deciding unit 3105 tries to select a combinationthat can be displayed according to the requested still resolution(S3503). As a result of it, the resolution selecting deciding unit 3105decides whether the resolution is changed to the requested to stillresolution or not (S3504), and conducts a still resolution changenotification to the still resolution managing unit 3103 if theresolution is changed (S3505). In accordance with this still resolutionchange, the resolution selecting deciding unit 3105 also decides whetherthe video resolution is changed or not (S3506), and conducts a videoresolution change notification to the video resolution managing unit3102 if the resolution is changed (S3507). In accordance with this stillresolution change, the resolution selecting deciding unit 3105 alsodecides whether an OSD resolution is changed or not (S3508), andconducts a still resolution change notification to the OSD resolutionmanaging unit 3101 if the resolution is changed (S3509).

FIG. 36 and FIG. 37 are flowcharts of the resolution selection decidingunit 3105 for a case that the resolution of the video format received bythe video decoder 508 is different from the resolution of the videoformat that has been decoded before. The video format resolution changedetecting unit 3104 notifies the video format resolution change to theresolution selection deciding unit 3105 (S3601). According to the videoformat resolution, the requested OSD resolution and the requested stillresolution, which are memorized in the primary storage unit 511, ittries to select a combination that can be displayed (S3602). As a resultof it, if there is no combination that can be displayed (S3603), ittries to select a combination that can be displayed according to thevideo format resolution and the requested OSD resolution memorized inthe primary storage unit 511(S3604). As a result of it, if there is nocombination that can be displayed (S3605), it tries to select acombination that can be displayed according to the video formatresolution (S3606). As a result of it, it decides whether the OSDresolution is changed or not (S3701). If it is changed, the OSDresolution change notification is made to an OSD resolution managingunit 3101 (S3702). It decides whether the video resolution is changed ornot, (S3703). If it is changed, the video resolution change notificationis made to the video resolution managing unit 3101 (S3704). It decideswhether the still resolution has been changed or not (S3705). If it ischanged, a still resolution change notification is made to the stillresolution managing unit 3101 (S3706).

For example, the application program 3100 is an application thatdisplays program contents, channel names and advertisements, etc. at acorner of the screen using the OSD plane regardless of details of theprogram and/or contents. In this case, as shown in FIG. 38, a videodisplay area 3802 occupies the main portion of a display screen 3800,whereas the OSD display area 3801 that displays the above application ina small portion. In this case, when its video format is changed, it isdesirable that the resolution selection deciding 3105 changes it to acombination that can be displayed according to the video format. Here,suppose that the video resolution is changed to 1920*1080 when both ofthe video plane and the OSD plane are being displayed with theresolution of 720*480. In this case, if the OSD plane resolution isprioritized, the video enlargement and reduction unit 520 needs toreduce the video of 1920*1080 stored in the video buffer 517 to 720*480.It apparently deteriorates its video quality. This application aims atdisplaying supplemental information. It is not desirable to deterioratethe video, which is the main information just for displaying thesupplemental information. Therefore, if the application program 3100does not issue a change request of the OSD resolution to the OSDresolution managing unit 3101, or does not issue a change request of thestill resolution to the still resolution managing unit 3102, it meansthat the video format change is prioritized. Then, the applicationprogram 3100 recognizes that the OSD plane resolution has been changed,and redraws characters and graphics suitable to the OSD resolution. Bydoing so, it becomes possible to provide a beautiful screen display.

On the other hand, suppose that the application program 3100 is anapplication that displays a video display in a small area and displaysan application display in its entire display area. To be more specific,JMF 1205 a provides functions to enlarge and reduce the video anddesignate its display location, and the application program 3100 usesthese functions. In this case, as shown in FIG. 39, an OSD display area3901, which is the display of the application, occupies the majorportion of a display screen 900, and a video display area 3902 is small.The size and ideographic location of the video display area 3901 aredecided according to the functions provided by the IMF1205 a. In thiscase, when the video format is changed, it is desirable that theresolution selection deciding unit 3105 changes the combinationaccording to the currently displayed OSD resolution. The reason isbecause the video has already been reduced and displayed in theapplication of which video quality is apparently deteriorated. Even ifthe OSD resolution is changed according to the change in the video planeresolution, it is inevitable to deteriorate the quality of the video. Onthe other hand, it is necessary for the application program 3100 toredraw the OSD display area 3901 according to the change in the OSDplane resolution. In general, a rendering process for a larger displayarea takes time. Also, it is necessary to prepare a plural number ofcharacters and graphics information according to the OSD planeresolution, which requires a lot of memories. In addition to it, theapplication program 3100 must be well-functioned to deal withcomplicated processes. Therefore, if the application program 3100 issuesa change request of desired OSD resolution to the OSD resolutionmanaging unit 3101, it means that the OSD resolution is prioritized. Asa result of this, there would be issues such as complications of theapplication program 3100 and how to retain extra characters and graphicsdata. Also, when the OSD plane resolution is prioritized, the videoenlargement and reduction unit 520 enlarges and reduces the video storedin the video buffer 517 to meet with the resolution retained.

Second Embodiment

In the first embodiment, for a case the video format is changed under asituation that the application program 3100 issues a change request ofthe OSD resolution to the OSD resolution managing unit 3101, the OSDresolution is prioritized. Therefore, there are some cases that thevideo format resolution change request may not be made in theapplication program 3100.

Therefore, in the present embodiment, as shown in a configurationdiagram of the video resolution switching function indicated in FIG. 40,for a case that the resolution of the video format received by the videodecoder 508 is different from the resolution of the video format thathas been decoded before, a video format resolution change detecting unit4001 has a function to also notify it to the application program 3100,in addition to the function of the video format resolution changedetecting unit 3104. Because other functions such as an OSD resolutionmanaging unit 3101, a video resolution managing unit 3102, a stillresolution managing unit 3103 and resolution selection deciding unit3105, which are contained in a resolution switching unit 1205 f, are thesame as those in the first embodiment, their explanations. are omitted.

By doing so, the application program 3100 can recognize the change inthe video format resolution, and by making a change request along withthe notified video format resolution to the video resolution managingunit 3102, it is possible to display the video with the resolution ofthe video format.

Third Embodiment

In the second embodiment, the application program 3100 can designateonly one OSD resolution at a time, which can display the applicationitself in the most appropriate way, to the resolution switching unit1205 f.

Therefore, in the present embodiment, as shown in the configurationdiagram of the video resolution switching function indicated in FIG. 41,the application program 3100 has a configuration to include the OSDresolution, which can display the application itself in the mostappropriate way, and resolution can be registered in advance in anoptimum resolution managing unit 4106.

The resolution switching unit 1205 f includes an OSD resolution managingunit 4101, a video resolution managing unit 4102, a still resolutionmanaging unit 4103, a video format resolution change detecting unit4104, a resolution selection deciding unit 4105, and an optimumresolution managing unit 4106, and has a video resolution switchingfunction. The OSD resolution managing unit 4101 controls the OSD planeresolution. The OSD resolution managing unit 4101 has a function toaccept a change request of the current OSD plane resolution from theapplication program 3100 and a function to notify the change in the OSDplane resolution to the application program 3100. When the changerequest of the OSD plane resolution is accepted, it is notified to theresolution selection deciding unit 4105.

The video resolution managing unit 4102 controls the video planeresolution. The video resolution managing unit 4102 has a function toaccept a change request of the current video plane resolution from theapplication program 3100 and a function to notify the change in thevideo plane resolution to the application program 3100. When the changerequest of the video plane resolution is accepted, it is notified to theresolution selection deciding unit 4105.

The still resolution managing unit 4103 controls the video planeresolution. The still resolution managing unit 4103 has a function toaccept a change request of the current video still resolution from theapplication program 3100 and a function to notify the change in thestill plane resolution to the application program 3100. When the changerequest of the still plane resolution is accepted, it is notified to theresolution selection deciding unit 4105.

For a case the video format resolution received by the video decoder 508is different from the resolution of the video format that has beendecoded before, the video format resolution change detecting unit 4104notifies it to the resolution selection deciding unit 4105 and theapplication program 3100.

The optimum resolution managing unit 4106 has a function to register anddelete the OSD resolution that the application program 3100 can displaythe application itself in the most appropriate way. It is possible forthe application program 3100 to register more than one OSD resolution.

FIG. 42 is a flowchart of the optimum resolution managing unit 4106 fora case that the application program 3100 registers the optimum OSDresolution. The application program 3100 requests to register theoptimum OSD resolution to be registered to the optimum resolutionmanaging unit 4106 (S4201). The optimum resolution managing unit 4106memorizes the requested optimum OSD resolution to the primary storageunit 511 (S4202).

FIG. 43 is a flowchart of the optimum resolution managing unit 4106 fora case that the application program 3100 deletes the optimum OSDresolution. The application program 3100 requests to delete the optimumOSD resolution to be deleted to the optimum resolution managing unit4106 (S4301). The optimum resolution managing unit 4106 deletes therequested optimum OSD resolution from the primary storage unit 511(S4302).

The resolution selection deciding unit 4105 selects resolution for eachplane along with consideration of a possible combination to be displayedamong each plane of the TV receiver for one of the following cases: fora case there is a request to change the current OSD plane resolution tothe OSD resolution managing unit 4101; for a case there is a request tochange the current video plane resolution to the video resolutionmanaging unit 4102; for a case there is a request to change the currentstill plane resolution to the still resolution managing unit 4103; andfor a case there is a request to change the video format resolution fromthe video format resolution change detecting unit 4104.

FIG. 44 is a flowchart of the resolution selection deciding unit 4105for a case there is a request to change the current OSD resolution tothe OSD resolution managing unit 4101. The OSD resolution managing unit4101 provides the OSD resolution to the resolution to the resolutionselection deciding unit 4105 and makes the change request (S4401). TheOSD resolution managing unit 4101 tries to select a combination to bedisplayed according to the OSD resolution requested to be changed(S4402). As a result of it, the OSD resolution managing unit 4101decides whether the requested OSD resolution is changed or not (S4403),and executes the OSD resolution change notification to the OSDresolution managing unit 4101 if it is changed (S4404). In accordancewith this OSD resolution change, the OSD resolution managing unit 4101decides whether the video resolution is changed (S4405), and executesthe video resolution change notification to the video resolutionmanaging unit 4102 if it is changed (S4406). In accordance with this OSDresolution change, the OSD resolution managing unit 4101 decides whetherthe still resolution is changed (S4407), and executes the videoresolution change notification to the video resolution managing unit4103 if it is changed (S4408).

FIG. 45 is a flowchart of the resolution selection deciding unit 4105for a case there is a request to change the current video planeresolution to the video resolution managing unit 4102. The videoresolution managing unit 4102 provides the video resolution to theresolution to the resolution selection deciding unit 4105 and makes thechange request (S4501). The video resolution managing unit 4102 tries toselect a combination to be displayed according to the video resolutionrequested to be changed (S4502). As a result of it, the video resolutionmanaging unit 4102 decides whether the requested video resolution ischanged or not (S4503), and executes the video resolution changenotification to the video resolution managing unit 4102 if it is changed(S4504). In accordance with this video resolution change, the videoresolution managing unit 4102 decides whether the OSD resolution ischanged (S4505), and executes the OSD resolution change notification tothe OSD resolution managing unit 4101 if it is changed (S4506). Inaccordance with this video resolution change, the video resolutionmanaging unit 4102 decides whether the still resolution is changed(S4507), and executes the video resolution change notification to thevideo resolution managing unit 4103 if it is changed (S4508).

FIG. 46 is a flowchart of the resolution selection deciding unit 4105for a case there is a request to change the current still planeresolution to the still resolution managing unit 4103. The stillresolution managing unit 4103 provides the still resolution to theresolution to the resolution selection deciding unit 4105 and makes thechange request (S4601). The still resolution managing unit 4103 tries toselect a combination to be displayed according to the still resolutionrequested to be changed (S4602). As a result of it, the still resolutionmanaging unit 4103 decides whether the requested still resolution ischanged or not (S4603), and executes the still resolution changenotification to the still resolution managing unit 4103 if it is changed(S4604). In accordance with this still resolution change, the stillresolution managing unit 4103 decides whether the video resolution ischanged (S4605), and executes the video resolution change notificationto the video resolution managing unit 4102 if it is changed (S4606). Inaccordance with this still resolution change, the still resolutionmanaging unit 4103 decides whether the OSD resolution is changed(S4607), and executes the OSD resolution change notification to the OSDresolution managing unit 4101 if it is changed (S4608).

FIG. 47 and FIG. 48 are flowcharts of the resolution selection decidingunit 4105 for a case the video format resolution received by the videodecoder 508 is different from the video format resolution that has beenchanged previously. The video format resolution change detecting unit4104 notifies the video format resolution change to the resolutionselection deciding unit 4105 (S4701). The video format resolution changedetecting unit 4104 sequentially acquires the optimum OSD resolutionmemorized in the primary storage unit 511 (S4702). The video is formatresolution change detecting unit 4104 decides whether the optimum OSDresolution is acquired or not (S4703). If it is acquired in the S4703,the video format resolution change detecting unit 4104 tries to select acombination to be displayed according to the video format resolution andthe acquired optimum OSD resolution (S4704). As a result of it, thevideo format resolution change detecting unit 4104 decides whether thereis a combination to be displayed or not (S4705). If there is thecombination in the S4705, it goes to S4801. If there is no combinationin the S4705, it goes back to the S4702. If the optimum OSD resolutioncannot be acquired in the S4703, i.e. the sequential acquirement of theoptimum OSD resolution is finished, it tries to select a combination tobe displayed according to the video format resolution (S4706). As aresult of the S4704 or the S4706, it decides whether the OSD resolutionis changed or not (S4801), and executes the OSD resolution changenotification to the OSD resolution managing unit 4101 (S4802) if the OSDresolution is changed. It decides whether the video resolution ischanged or not (S4803), and executes the video resolution changenotification to the video resolution managing unit 4102 (S4804) if thevideo resolution is changed. It decides whether the still resolution hasbeen changed or not (S4805), and executes the still resolution changenotification to the still resolution managing unit 4103 (S4806) if thestill resolution is changed.

By doing so, the application program 3100 is able to register a pluralnumber of the OSD resolution, which can display the application itselfin the most appropriate way, to the resolution switching unit 1205. Whenthe application program 3100 is able to handle the plural number ofresolution, it can provide more opportunities to display the video andthe application without causing any distortion according to the changein the video format resolution.

Fourth Embodiment

In the third embodiment, when a plural number of applications like theapplication program 3100 exist and are displayed, there are some casesthat it becomes uncertain which of the application programs thatregisters the optimum OSD resolution should be used as a basis fordeciding a displayable combination.

Therefore, in the present embodiment, as shown in FIG.49 sets (4901,4902, 4903, etc.) of a Java program identifier 4900, which can identifyan application program, and the optimum OSD resolution are registered inthe optimum resolution managing unit 4106, and a priority 2005 shown inFIG. 20 is acquired from the registered sets of the Java programidentifier (4901, 4902, 4903, etc.) and the optimum OSD resolution, anda combination to be displayed is decided by using the priority 2005 atthe time of the decision. Other functions such as the OSD resolutionmanaging unit 4101, the video resolution managing unit 4102, the stillresolution managing unit 4103, and the video format resolution changedetecting unit 4104 contained in the resolution switching unit 1205 fstay the same.

The following describes processes of the optimum resolution managingunit 4106 and the resolution selection deciding unit 4105, of whichfunctions are different.

FIG. 50 is a flowchart of the optimum resolution managing unit 4106 fora case that the application program 3100 registers the optimum OSDresolution. The application program 3100 requests to register theoptimum OSD resolution to be registered to the optimum resolutionmanaging unit 4100 (S5001). The optimum resolution managing unit 4106acquires the lava program identifier of the application programrequesting the registration (S5002). The optimum resolution managingunit 4106 memorizes a set of the acquired Java program identifier andthe optimum requested OSD resolution in the primary storage unit 511(S5003).

FIG. 51 is a flowchart of the optimum resolution managing unit 4106 fora case the application program 3100 deletes the optimum OSD resolution.The application program 3100 requests to register the optimum OSDresolution to be deleted to the optimum resolution managing unit 4106(S5101). The optimum resolution managing unit 4106 acquires the Javaprogram identifier of the application program requesting the deletion(S5102). The optimum resolution managing unit 4106 memorizes the set ofthe acquired Java program identifier and the deletion-requested optimumOSD resolution from the primary storage unit 511 (S5103).

FIG. 52, FIG. 53 and FIG. 54 are flowcharts of the resolution selectiondeciding unit 4105 for a case that the resolution of the video formatreceived by the video decoder 508 is different from the resolution ofthe video format that has been previously decoded. The video formatresolution change detecting unit 4104 notifies a video format resolutionchange to the resolution selection deciding unit 4105 (S5201). Theresolution selection deciding unit 4105 sequentially acquires sets ofthe Java program identifier and the optimum OSD resolution memorized inthe primary storage unit 511 (S5202). The resolution selection decidingunit 4105 decides whether the set of Java program identifier and theoptimum OSD resolution is acquired (S5203). If it is acquired in theS5203, the resolution selection deciding unit 4105 tries to select acombination to be displayed according to the video format resolution andthe optimum OSD resolution in the acquired set (S5204). As a result ofthe S5204, the resolution selection deciding unit 4105 decides if thereis the displayable combination or not (S5205). If there is thecombination in the S5205, the resolution selection deciding unit 4105memorizes all of the displayable combination and Java programidentifiers in a maintenance storage unit 511 (S5206), and goes back tothe S5203. If there is no combination in the S5205, it goes back toS5202. For a case the set of the Java program identifier and the optimumOSD resolution cannot be acquired in the S5203, i.e. sequentialacquirement of the optimum OSD resolution is finished, the resolutionselection deciding unit 4105 decides whether there is a set of the Javaprogram identifier and the optimum OSD resolution memorized in the S5206(S5301). If there is the memorized set(s) in the S5301, the resolutionselection deciding unit 4105 sequentially acquires the set of thedisplayable combination and the Java program identifier from the primarystorage unit 511 (S5302), acquires a priority corresponding to the Javaprogram identifier in each of the sets from the secondary storage unit510, compares them, and extracts the displayable combination with thehighest priority (S5303). If there is no set memorized in the S5301, theresolution selection deciding unit 4105 tries to select a displayablecombination according to the video format resolution (S5304). As resultsof S5303 and S5304, the resolution selection deciding unit 4105 decideswhether the OSD resolution is changed or not (S5401), and conducts theOSD resolution change notification to the OSD resolution managing unit4101 if it is changed (S5402). The resolution selection deciding unit4105 decides whether the video resolution is changed or not (S5403), andconducts the video resolution change notification to the videoresolution managing unit 4102 if it is changed (S5404). The resolutionselection deciding unit 4105 decides whether the still resolution ischanged or not (S5405), and conducts the still resolution changenotification to the still resolution managing unit 4103 if it is changed(S5406).

By doing so, even if a plural number of application programs exist andare displayed, it can decide video resolution of the displayablecombination along with consideration of all of the optimum OSDresolution respectively registered by each application program.

Fifth Embodiment

In the second embodiment, action of the resolution selection decidingunit 4105 may be defined in the way described in FIG. 55 and FIG. 37.The video format resolution change detecting unit 3104 notifies thevideo format resolution change to the resolution selection deciding unit3105 (S3601). The resolution selection deciding unit 4105 tries toselect a combination to be displayed according to the video formatresolution, the current OSD resolution and the current still resolution(S5502). As a result of it, if there is no combination to be displayed(S3603), the resolution selection deciding unit 4105 tries to select acombination to be displayed that can maintain the current OSD planeresolution (S5504). As a result of it, if there is no combination to bedisplayed (S3605), the resolution selection deciding unit 4105 tries toselect a combination to be displayed according to the video formatresolution (S3606). As a result of it, the resolution selection decidingunit 4105 decides whether the OSD resolution is change or not (S3701),and conducts the OSD resolution change notification to the OSDresolution managing unit 3101 if it is changed (S3702). The resolutionselection deciding unit 4105 decides whether the video resolution ischanged or not (S3703), and conducts the video resolution changenotification to the video resolution managing unit 3102 if it is changed(S3704). The resolution selection deciding unit 4105 decides whether thestill resolution is changed or not (S3705), and conducts the stillresolution change notification to the still resolution managing unit3103 if it is changed (S3706).

Having these actions make it possible to maintain the OSD planeresolution preferentially. In the first embodiment, as shown in FIG. 39,it is possible to realize the application that centrally keeps the OSDplane resolution. In the first embodiment, this type of the applicationneeds to issue a request to change the desired OSD resolution to the OSDresolution managing unit 3101. However, in the present embodiment, thereis no need for that. In the present embodiment where the applicationthat prioritizes the video plane resolution, just as shown in FIG. 38,when a format of the video stored in the video decoder 508 is notifiedfrom the resolution selection deciding unit 3105. It is possible toprioritize the video plane resolution by issuing the change request ofthe OSD plane resolution to the OSD resolution managing unit 3101according to the format.

In the present embodiment, the OSD plane resolution is supposed to beprioritized. However, in the flowchart of FIG. 55, it is possible tohave the step S5504 be treated as a step “to try to select a combinationto be displayed, which can maintain the video format resolution notifiedto be changed”. By doing so, even though the application designates theOSD plane resolution, the video plane resolution is prioritized. Asshown in FIG. 38, it can easily realize the application that prioritizesthe video plane resolution.

Also, though the OSD plane resolution is supposed to be prioritized inthe present embodiment, the step S5504 in the flowchart of FIG. 55 maybe a step “to try to select a combination to be displayed that canmaintain the current still resolution”. By doing so, even though theapplication designates the OSD plane resolution, the still planeresolution is prioritized. As shown in FIG. 38, it can easily realizethe application that prioritizes the still plane resolution.

In the present embodiment, it is also possible to add a priority planeaccepting unit that accepts designation of the plane to be prioritized.The application program 3100 designates the plane to be prioritized tothe priority plane accepting unit. In this case, the priority planeaccepting unit memorizes the accepted plane to the primary storage unit511. The resolution selection deciding unit 4105 makes the step S5504 inthe flowchart of FIG. 55 be a step “to try to select a combination to bedisplayed that can maintain the plane resolution retained by the primarystorage unit 511”.

As a result of this, the application is easily capable of designatingthe plane of which resolution needs to be maintained.

In addition to this, it is possible for the priority plane acceptingunit to accept the first priority plane and the second priority plane.The application program 3100 designates the first priority plane and thesecond priority plane to the priority plane accepting unit. At thistime, the priority plane accepting unit memorizes the accepted firstpriority plane and the accepted second priority plane in the firststorage unit 511. The resolution selection deciding unit 4105 shall havethe step S5504 in the flowchart of FIG. 55, which “tries to select acombination to be displayed that can maintain the resolutions in thefirst priority plane and the second priority plane retained by the firststorage unit 511, and tries to select a combination to be displayed thatcan maintain the resolution of the first priority plane if both of themcannot be compossible”.

Sixth Embodiment

In the first embodiment, when two applications indicated in FIG. 38 andFIG. 39 are being executed at the same time, it is necessary to decidewhich of the applications should be prioritized. In the presentembodiment, the structure of the resolution switching unit 1205 f in thefirst embodiment shall be the structure in FIG. 56. Since the structuralcomponents having the same number as those in the FIG. 31 have the samefunction, their explanation is omitted here. A change permitting unit5601 permits a change request of the application program 3100. Theapplication program 3100 obtains change permission from the changepermitting unit 5601 before making a change request of the resolution tothe OSD resolution managing unit 5602, the video resolution managingunit 5603, and the still resolution managing unit 5604. After thepermission is obtained, it makes the necessary change request. If thechange request becomes unnecessary, it notifies that the permission isno longer necessary to the change permitting unit 5601. When otherapplication makes a permission request after the permission is issued,the change permitting unit 5601 compares which of two applications has ahigher priority and decides which of the applications is permitted. Interms of the priorities of applications, the change permitting unit 5601may refer to the priorities pre-assigned to the applications, which isas explained in the example of FIG. 20 in the first embodiment, or theapplication program 3100 may provide such information to the changepermitting unit 5601. The OSD resolution managing unit 5602, the videoresolution managing unit 5603 and the still resolution managing-unit5604, in addition to functions of the OSD resolution managing unit 3101,the video resolution managing unit 3102 and the still resolutionmanaging unit 3103, do not accept a request from the application program3100, which is not permitted by the change permitting unit 5601. Byrealizing the present embodiment, it becomes possible to clarify whetherrequests from multiple applications are accepted or not so that multipleapplications can be operated at the same time.

Seventh Embodiment

With reference to diagrams, the following describes embodiment of acable TV system according to the present invention. FIG. 1 is a blockdiagram that shows a relationship of an apparatus comprising a cablesystem, which includes a head end 101 and three terminal apparatusesA101, B112 and C113. In the present embodiment, three terminalapparatuses are connected to one head end. However, the presentinvention may also be embodied by having a designated number of terminalapparatuses that are connected to the head end.

The head end 101 sends a broadcasting signal of video, audio and data,etc. to a plural number of terminal apparatuses, and also receives datasent from the terminal apparatus. In order to realize this, a frequencybandwidth used for transmission between the head end 101 and terminalapparatuses A111, B112 and C113 is divided for use. FIG. 2 is a chartthat shows an example of the divided frequency bandwidth. The bandwidthcan be roughly divided into two types; Out Of Band (so-called OOB) andIn-Band. 5 to 130 MHz are assigned to OOB, and mainly used for datacommunication between the head end 101 and terminal apparatuses A111,B112 and C113. 130 MHz to 864 MHz are assigned to the In-Band, andmainly used for a broadcasting channel that includes video and audio. AQPSK modulation method is used for OOB, and a QAM64 modulation method isused for In-Band. The modulation technology is a publicly knowntechnology, which is not so closely tied up with the present invention,so that its detailed explanation is omitted here. FIG. 3 is an exampleof further detailed use of the OOB frequency bandwidth. 70 MHz to 74 MHzare used for data transmission from the head end 101, and all of theterminal apparatuses A111, B112 and C113 are supposed to receive thesame data from the head end 101. On the other hand, 10.0 MHz to 10.1 MHzare used for data transmission from the terminal apparatus A111 to thehead end 101, 10.1 MHz to 10.2 MHz are used for data transmission fromthe terminal apparatus B112 to the head end 101, and 10.2 MHz to 10.3MHz are used for data transmission from the terminal apparatus C113 tothe head end 101. By doing so, unique data in each terminal apparatuscan be individually sent from each of the terminal apparatuses A111,B112 and C113 to the head end 101. FIG. 4 is an example showing how afrequency bandwidth of the In-Band is used. 150 to 156 MHz and 156 to162 MHz are respectively assigned to a TV channel 1 and a TV channel 2,and following frequency bandwidths at intervals of 6 MHz are assigned toeach corresponding TV channel. A frequency bandwidth of 310 MHz andbigger are respectively assigned to radio channels by each 1 MHz unit.Each of these channels may also used for analogue broadcasting or fordigital broadcasting. For a case of the digital broadcasting, data istransmitted in a transport packet format based on MPEG 2 specifications,and also data for various data broadcasting can be sent in addition toaudio and video.

The head end 101 contains a QPSK modulation unit and a QAM modulationunit, etc. for sending an appropriate broadcasting signal to thesefrequency bandwidths. Also, it is considered that the head end 101 hasvarious devices related to these modulation units and demodulationunits. However, because the present invention mainly relates to terminalapparatuses, its detailed explanation is omitted here.

The terminal apparatus A111, the terminal apparatus B112 and theterminal apparatus C113 receive and reproduce the broadcasting signalfrom the head end 101. Also, these apparatuses send unique data of eachterminal apparatus to the head end 101. These three terminal apparatuseshave the same structure in the present embodiment.

FIG. 5 is a block diagram that shows a hardware configuration of theterminal apparatus. 500 is a terminal apparatus that includes a QAMdemodulation unit 501, a QPSK demodulation unit 502, a QPSK modulationunit 503, a TS decoder 505, an audio decoder 506, a speaker 507, a videodecoder 508, a display 509, a secondary storage unit 510, a primarystorage unit 511, a ROM 512, an input unit 513, a CPU 514, a stilldecoder 515, an OSD controlling unit 516, a video buffer 517, a stillbuffer 518, an OSD buffer 519, a video enlargement and reduction unit520, a still enlargement and reduction unit 521, an OSD enlargement andreduction unit 522, a composing unit 523. Also, a POD 504 is installedto and detached from the terminal apparatus 500.

FIG. 6 is a thin shaped television as one of the examples for an outlookof the terminal apparatus 500.

601 is a steel case of the thin shaped television, which has all ofstructural components of the terminal apparatus 500 in it with anexception of the POD 504.

602 is a display, which is equivalent to the display 509 shown in FIG.5.

603 is a front panel unit combining of a plural number of buttons, whichis equivalent to the input unit 513 in FIG. 5.

604 is a signal input terminal that connects a cable for sending andreceiving a signal to/from the head end 101. The signal input terminalis connected to the QAM demodulation unit 501, the QPSK demodulationunit 502 and the QPSK modulation unit 503.

605 is a POD card, which is equivalent to the POD 504 in FIG. 5. Justlike the POD card 605 in FIG. 6, the POD 504 has an independentconfiguration from the terminal apparatus 500 and is attached to anddetached from the terminal apparatus 500. Details of the POD 504 will beexplained later.

606 is an insertion slot to which the POD card 605 is inserted.

With reference to FIG. 5, the QAM demodulation unit 501 demodulates asignal which has been QAM-modulated in and sent by the head end 101according to tuning information containing a frequency designated fromthe CPU 514, and passes it to the POD 504.

The QPSK demodulation unit 502 demodulates a signal which has beenQPSK-modulated in and sent by the head end 101 according to tuninginformation containing a frequency designated from the CPU 514, andpasses it to the POD 504.

The QPSK modulation unit 503 QPSK-modulates a signal sent by the POD 504according to modulation information containing a frequency designatedfrom the CPU 514, and passes it to the head end 101.

The POD 504 has a configuration that is detachable from the terminalapparatus body 500 as shown in FIG. 6. A connection interface betweenthe terminal body 500 and the POD 504 is defined in OpenCable™ HOST-PODInterface Specification (OC-SP-HOSTPOD-IF-I12-030210) and aspecification document referred by this specification document. Here,its detail is omitted, and only the part concerned for the presentinvention is explained.

FIG. 7 is a block diagram that shows an internal configuration of thePOD 504. The POD 504 includes a first descrambler unit 701, a seconddescrambler unit 702, a scrambler unit 703, a first storage unit 704, asecond storage unit 705 and a CPU 706.

The first descrambler unit 701 receives a signal scrambled from the QAMdemodulation unit 501 of the terminal apparatus 500 and descrambles itaccording to an instruction from the CPU 706. Then, the signaldescrambled is sent to the TS decoder 505 of the terminal apparatus 500.Information necessary for decoding, such as a key, is provided from theCPU 706 as needed. To be more specific, the head end 101 broadcastsseveral paid channels. If a user subscribes this paid channel, the firstdescrambler unit 701 receives necessary information, such as a key, anddescrambles its content so that the user can view the paid channel. Ifthe necessary information, such as a key, is not provided, the firstdescrambler unit 701 does not execute the descrambling process, andsends the received signal as it is to the TS decoder 505.

According to an instruction from the CPU 706, the second descramblerunit 702 receives a signal scrambled from the QPSK demodulation unit 502of the terminal apparatus 500 and descrambles it. Then, the seconddescrambler unit 702 passes the descrambled data to the CPU 706.

According to an instruction from the CPU 706, the scrambler unit 703scrambles the data received from the CPU 706 and sends it to the QPSKmodulation unit 503 of the terminal apparatus 500.

The first storage unit 704 is made up of a primary memory, which isspecifically something like a RAM, etc. and is used for temporarilystoring data when the CPU 706 executes a process.

The second storage unit 705 is made up of a secondary memory, which isspecifically something like a flash ROM, etc., and is used for storing aprogram executed by the CPU 706, and also for saving data that shouldnot be deleted even if its power is turned off.

The CPU 706 executes a program memorized in the second storage unit 705.The program is made up of a plural number of subprograms. FIG. 8 is asample program memorized in the second storage unit 705. In FIG. 8, theprogram 800 is made up of a main program 801 and a plural number ofsubprograms such as an initialization subprogram 802, a networksubprogram 803, a reproduction subprogram 804, a PPV subprogram 805,etc.

The PPV here is an acronym of Pay Per View, which is a service to allowspecific programs such as movies to be viewed with a certain charge.When a user enters a personal identification number, his subscription isnotified to the head end 101, and its scramble is removed for viewing.The user will pay the subscription fee later for this view.

The main program 801 is a subprogram started at first by the CPU 706when the power is turned on, and controls other subprograms.

The initialization subprogram 802 is started by the main program 801when the power is turned on, exchanges information, etc. with theterminal apparatus 500 and executes an initialization process. Detailsof the initialization process are defined in OpenCable™, HOST-PODInterface Specification (OC-SO-HOSTPOD-IF-I12-030210) and aspecification document referred by this specification document. Also, aninitialization process that is not defined in the specification is alsoexecuted. Here, a part of it is introduced. When the power is turned on,the initialization subprogram 802 notifies a first frequency memorizedin the second storage unit 705 to the QPSK demodulation unit 502 throughthe CPU 514 of the terminal apparatus 500. The QPSK demodulation unit502 executes a tuning process with the first frequency provided, andsends a signal to the second descrambler unit 702. Also, theinitialization subprogram 802 provides descramble information such as afirst key memorized in the second storage unit 705 to the seconddescrambler unit 702. As a result of it, the second descrambler unit 702executes descrambling and passes the outcome to the CPU 706 thatexecutes the initialization subprogram 802. Therefore, theinitialization subprogram 802 can receive the information. In thepresent embodiment, the initialization subprogram 802 is supposed toreceive the information via the network subprogram 803. Its detail willbe explained later.

Additionally, the initialization subprogram 802 notifies the secondfrequency memorized in the second storage unit 705 to the QPSKdemodulation unit 503 via the CPU 514 of the terminal apparatus 500. Theinitialization subprogram 802 provides scramble information memorized inthe second storage unit 705 to the scrambler unit 703. When theinformation to be sent by the initialization subprogram 802 is providedto the scrambler unit 703 via the network subprogram 803, the scramblerunit 703 scrambles the data using the scramble information provided andpasses it to the QPSK demodulation unit 503 of the terminal apparatus500. The QPSK demodulation unit 503 demodulates the scrambledinformation provided and sends it to the head end 101.

As a result of this, the initialization subprogram 802 is capable ofconducting interactive communications with the head end 101 through theterminal apparatus 500, the second descrambler unit 702, the scramblerunit 703 and the network subprogram 803.

The network subprogram 803 is a subprogram for conducting interactivecommunications with the head end 101, which is used by a plural numberof subprograms such as the main program 801 and the initializationsubprogram 802. To be more specific, it acts like having interactivecommunications with the head end 101 through TCP/IP for othersubprograms that use the network subprogram 803. TCP/IP is a well knowntechnology that stipulates a protocol for information exchanges betweena plural number of apparatuses, and its detail explanation is omittedhere. The initialization subprogram 802 is started when the power isturned on, and the network subprogram 803 notifies a MAC address (anacronym of Media Access Control address), which is an identifieridentifying POD 504 memorized by the is second storage unit 705 inadvance, and-request to obtain the IP address. The head end 101 notifiesthe IP address to the POD 504 via the terminal apparatus 500, and thenetwork subprogram 803 memorizes the IP address in the first storageunit 704. From this point, the head end 101 and the POD 504 use this IPaddress as an identifier of the POD 504, and conducts communications.

The reproduction subprogram 804 provides descramble information such asa second key, etc., which is memorized in the second storage unit 705,and descramble information such as a third key, etc., which is providedfrom the terminal apparatus 500, to the first descrambler unit 701, andenables a descrambling process. Also, it receives via the networksubprogram 803 information that the signal entered in the firstdescrambler unit 701 is a PPV channel. When it recognizes that it is PPVchannel, it starts the PPV subprogram 805.

When the PPV subprogram 805 is started, it displays a message to promptsubscription of a program on the terminal apparatus 500, and receivesthe user's input. To be more specific, when information to be displayedon a screen is sent to the CPU 514 of the terminal apparatus 500, aprogram that activates on the CPU 514 of the terminal apparatus 500displays a message on the display 509 of the terminal apparatus 500.When the user enters a personal identification number through the inputunit 513 of the terminal apparatus 500, the CPU 514 of the terminalapparatus 500 receives it and notifies it to the PPV subprogram 815 thatactivates on the CPU 706 of the POD504. The PPV subprogram 805 sends thereceived personal identification number to the head end 101 via thenetwork subprogram 803. When the personal identification number iscorrect, the head end 101 notifies descramble information such as afourth key, which is necessary for descramble, to the PPV subprogram viathe network subprogram 803. The PPV subprogram 805 provides the receivedthe descramble information such as the fourth key to the firstdescrambler unit 701, and the first descrambler unit 701 descrambles theentered signal.

With reference to FIG. 5, the TS decoder 505 filters the signal receivedfrom the POD 504, and provides necessary data to the audio decoder 506,the video decoder 508 and the CPU 514. The signal coming from the POD504 here is an MPEG2 transport stream. Details of the MPEG2 transportstream are described in the IOS/IEC13818-1 as an MPEG standard document,and their explanation is omitted here in the present embodiment. TheMPEG 2 transport stream is made up of a plural number of fixed lengthpackets, and a packet ID is assigned to each packet. FIG. 9 is a packetconfiguration diagram. 900 is a packet structured in a fixed length of188 bytes. The first 4 bytes are a header 901 that stores packetidentification information, and the remaining 184 bits are a payload 902that contains information to be sent. 903 is a breakdown of the header901. The packet ID is contained in 13 bits from the 12th bit to the 24thbit. FIG. 10 is a pattern diagram that expresses a plural number ofpacket columns to be sent. A packet 1001 has a packet ID “1” in itsheader and a payload contains first information of video A. A packet1002 has a packet ID “2” in its header and a payload contains firstinformation of audio A. A packet 1003 has a packet ID “3” in its headerand the payload contains first information of audio B.

A packet 1004 has a packet ID “1” in its header, a payload containssecond information of the video A, which is the subsequent informationof the packet 1001. In a similar way to this, packets 1005, 1026 and1027 contain subsequent data of other packets. In a way like this, whencontents of the packet payloads containing the same packet ID areconcatenated, continued video or audio can be reproduced.

With reference to FIG. 10, when the CPU 514 designates the packet ID “1”and a “video decoder 508” as an output destination to the TS decoder505, the TS decoder 505 extracts a packet with the packet ID “1” fromthe MPEG 2 transport stream received from the POD 504, and passes it tothe video decoder 508. In FIG. 10, only the video data is passed to thevideo decoder 508. At the same time, when the CPU 514 designates thepacket ID “2” and the “audio decoder 506” to the TS decoder 505, the TSdecoder 505 extracts a packet with the packet ID “2” from the MPEG2transport stream received from the POD 504, and passes it to the audiodecoder 506. In FIG. 10, only the audio data is passed to the audiodecoder 506.

A process to extract only a necessary packet according to this packet IDis a filtering process conducted by the IS decoder 505. The TS decoder505 can executes a plural number of filtering processes designated fromthe CPU 514 at the same time.

With reference to FIG. 5, the audio decoder 506 concatenates audio dataembedded in the packets of MPEG2 transport stream provided from the TSdecoder 505, executes digital-analog conversion, and outputs it to aspeaker 507.

The speaker 507 outputs a signal provided from the audio decoder 506 asaudio.

The video decoder 508 decodes the video data, which is embedded in thepacket of the MPEG2 transport stream provided from the TS decoder 505,using the provided video resolution, and stores the decoded video datainto the video buffer 517. Here, the provided video resolution is passedfrom the video resolution managing unit 3102 to be described later tothe video decoder 508, which then stores the received video resolutioninto the video buffer 517.

Furthermore, when no video resolution is provided to the video decoder508, a default video resolution is used.

It is also possible that the video resolution managing unit 3102 storesthe video resolution into the video buffer 517 and the video decoder 508refers to such video resolution stored in the video buffer 517 so as todecode it at the time of decoding.

Also, the video decoder 508 reads video information such as theresolution of video data and a ratio of height and width of the video,e.g. 4 to 3 or 16 to 9, and detects any changes in the videoinformation. The information detected is notified to the video formatresolution change detecting unit 3104, which is explained later.

The still decoder 515 decodes MPEG-I frame data (also referred to asstill data), which is designated from the CPU 514, using the providedstill resolution, and stores the decoded still data into the stillbuffer 518. Here, the provided still resolution is passed from the stillresolution managing unit 3103 to be described later to the still decoder515, which then stores the received still resolution into the stillbuffer 518. When no still resolution is provided to the still decoder515, a default still resolution is used.

It is also possible that the still resolution managing unit 3103 storesthe still resolution into the still buffer 518, and the still decoder515 refers to such still resolution stored in the still buffer 518 so asto decode it at the time of decoding. Because details of the MPEG2-Iframe are described in ISO/IEC13818-2 as an MPEG standard document, itsdetailed explanation is omitted here in the present embodiment.

The OSD controlling unit 516 stores, into the OSD buffer 519, OSD data(also referred to as graphics data) which is designated from the CPU514, using the provided OSD resolution. Alternatively, the OSDcontrolling unit 516 transfers, to the OSD buffer 519, the contents ofthe off-screen buffer of the primary storage unit 511 at high speed inwhich characters and graphics are drawn while performing alpha blending.Refer to DVB-MHP specification for details on alpha blending. Here, theprovided OSD resolution is passed from the OSD resolution managing unit3101 to be described later to the OSD controlling unit 516, which thenstores the received OSD resolution into the OSD buffer 519. When no OSDresolution is provided to the OSD controlling unit 516, a default OSDresolution is used.

Furthermore, it is also possible that the OSD resolution managing unit3101 stores the OSD resolution into the OSD buffer 519.

Also, the components of the OSD controlling unit 516 may be implementedas software and components implemented as hardware may be deleted.

The video buffer 517, a concrete constituent element of which is amemory and the like, is a buffer for storing a video resolution providedto the video decoder 508 as well as video data decoded by the videodecoder 508. Note that the video resolution is provided from the videoresolution managing unit 3102 to be described later.

The still buffer 518, a concrete constituent element of which is amemory and the like, is a buffer for storing a still resolution providedfrom the still decoder 515 as well as still data decoded by the stilldecoder 515. Note that the still resolution is provided from the stillresolution managing unit 3103 to be described later.

The OSD buffer 519, a concrete constituent element of which is a memoryand the like, is a buffer for storing an OSD resolution provided fromthe OSD controlling unit 516 as well as OSD data transferred from theOSD controlling unit 516. Note that the OSD resolution is provided fromthe OSD resolution managing unit 3101 to be described later.

According to a provided enlargement/reduction ratio, the videoenlargement and reduction unit 520 enlarges or reduces the video datastored in the video buffer 517, and passes the resultant to thecomposing unit 523. Here, such enlargement/reduction ratio is passedfrom the video resolution managing unit 3102 to be described later. Whenno enlargement/reduction ratio is provided, a defaultenlargement/reduction ratio is used.

According to a provided enlargement/reduction ratio, the stillenlargement and reduction unit 521 enlarges or reduces the still datastored in the still buffer 518, and passes the resultant to thecomposing unit 523. Here, such enlargement/reduction ratio is passedfrom the still resolution managing unit 3103 to be described later. Whenno enlargement/reduction ratio is provided, a defaultenlargement/reduction ratio is used.

According to a provided enlargement/reduction ratio, the OSD enlargementand reduction unit 522 enlarges or reduces the OSD data stored in theOSD buffer 519, and passes the resultant to the composing unit 523.Here, such enlargement/reduction ratio is passed from the OSD resolutionmanaging unit 3101 to be described later. When no enlargement/reductionratio is provided, a default enlargement/reduction ratio is used.

The composing unit 523 follows a Z order of each buffer designated fromthe CPU 514, and superposes the video data passed from the videoenlargement and reduction unit 520, the still data passed from the stillenlargement and reduction unit 521 and the OSD data passed from the OSDenlargement and reduction unit 522, and outputs the resultant to thedisplay 509. In order to explain the Z order of each buffer designatedfrom the CPU 514, a general TV receiver has three layered structure,which has an OSD buffer displaying characters and graphics, a videobuffer displaying video, and a still buffer displaying a still image,and its order of the superposition is called as Z order. For example,with reference to FIG. 57, if 5701 is a first buffer viewed at a frontside from a viewer, 5702 is a second buffer that is located at a backside of 5701, and 5703 is a third buffer that is located at the furthestback, there are six possible combinations as described in FIG. 58.

The display 509 is, to be more specific, made up of a cathode-ray tube,a liquid crystal display, etc., which outputs a video signal providedfrom the video decoder 508, and displays a message designated from theCPU 514.

The secondary memory 510, to be more specific, is made up of a flashmemory, hard disk, etc., which stores and deletes data or programsdesignated from the CPU 514. Also, the data and the programs stored arereferred to by the CPU 514. The data and the programs stored remain tobe stored even if the power of the terminal apparatus 500 is turned off.

The primary storage unit 511 is, to be more specific, made up of RAM,etc., which temporarily stores and deletes data and programs designatedby the CPU 514. Additionally, the data and the programs stored arereferred by the CPU 514. The data and the programs stored are clearedwhen the power of the terminal apparatus 500 is turned off.

ROM 512 is a memory device that cannot be rewritten, which is, to bemore specific, made up of ROM, CD-ROM, DVD, etc. The ROM 512 stores aprogram executed by the CPU 514.

The input unit 513 is, to be more specific, made up of a front panel anda remote controller, which accepts an input from the user. FIG. 11 is anexample for a case that the input unit 513 is made up of the frontpanel. 1100 is a front panel, which is equivalent to the front panel 603in FIG. 6. The front panel 1100 includes 7 buttons, an up cursor button1101, a down cursor button 1102, a left cursor button 1103, a rightcursor button 1104, an OK button 1105, a cancel button 1106 and an EPGbutton 1107. When the user presses one of the buttons, an identifier ofthe pressed button is notified to the CPU 514.

The CPU 514 executes a program memorized in the ROM 512. According tothe program executed, the CPU 514 controls the QAM demodulation unit501, the QPSK demodulation unit 502, the QPSK modulation unit 503, thePOD 504, the TS decoder 505, the display 509, the secondary storage unit510, the primary storage unit 511 and the ROM 512.

FIG. 12 is an example of a configuration diagram for the programmemorized in the ROM 512 and executed by the CPU 514.

A program 1200 is made up of a plural number of subprograms, which is,to be more specific, made up of an OS 1201, an EPG 1202, a Java VM 1203,a service manager 1204 and a Java library 1205.

The OS 1201 is a subprogram that is started by the CPU 514 when thepower of the terminal apparatus 500 is turned on. The OS 1201 is anabbreviation of Operation System, and its example is Linux, etc. The OS1201 is a generic name for a publicly well-known technology made up of akernel 1201 a, which concurrently executes other subprograms, and alibrary 1201 b, and its detailed explanation is omitted here. In thepresent embodiment, the kernel 1201 a of the OS 1201 executes the EPG1202 and the Java VM 1203 as a subprogram. Also, the library 1201 bprovides a plural number of functions for controlling structuralelements held by the terminal apparatus 500 for these subprograms.

As one of the functions, a tuning function is introduced here. With thetuning function, tuning information that includes a frequency isreceived from other subprograms, and passed to the QAM demodulation unit501. Accordingly, it becomes possible for the QAM demodulation unit 501to execute a demodulation process based on the provided tuninginformation, and to pass the demodulated data to the POD 504. As aresult of this, other subprogram can control the QAM demodulator via thelibrary 1201 b.

The EPG is made up of a program display unit 1202 a that displays a listof programs to the user and accepts an input from the user, and areproduction unit 1202 b that select a channel. The EPG stated here isan acronym of Electric Program Guide.

When the power of the terminal apparatus 500 is turned on, the EPG 1202is started by the kernel 1201 a. Within the EPG 1202 started, theprogram display unit 1202 a waits for an input from the user via theinput unit 513 of the terminal apparatus 500. When the input unit 513 ismade up of a front panel indicated in FIG. 11 and the user presses theEPG button 1107 of the input unit 513, an identifier of the EPG buttonis notified to the CPU 514. The program display unit 1202 a of the EPG1202, which is a subprogram activated on the CPU 514, receives thisidentifier, and displays program information on the display 509. FIG.13(1) and FIG. 13(2) are examples of program charts displayed on thedisplay 509. With reference to FIG. 13(1), the display 509 displays theprogram information in a grid pattern. Time schedule information isdisplayed in a column 1301. A channel name “Channel 1” and a programshown in a time zone corresponding to the time schedule in the column1301 are displayed in a column 1302. It shows that a program called“News 9” is televised from 9:00 to 10:30 and a program called “MovieAAA” is televised from 10:30 to 12:00 on the “Channel 1”. In the sameway as the column 1302, a channel name “Channel 2” and a program shownin a time zone corresponding to the time schedule in the column 1301 areshown in a column 1303. It shows that a program called “Movie BBB” istelevised from 9:00 to 11:00 and a program called “News 11” is televisedfrom 11:00 to 12:00. 1330 is a cursor. The cursor 1330 is moved bypressing the left cursor 1103 and the right cursor 1104 on the frontpanel 1100. In a situation of FIG. 13(1), the cursor 1330 is moved to aright side when the right cursor 1104 is pressed down, which is as shownin FIG. 13(2). Also, in a situation of FIG. 13(2), the cursor 1330 ismoved to a left side when the left cursor 1103 is pressed down, which isas shown in FIG. 13(1).

In a situation of FIG. 13(1), when an OK button 1105 of the front panel1100 is pressed down, the program display unit 1202 a notifies anidentifier of the “Channel 1” to the reproduction unit 1202 b. In asituation of FIG. 13(2), when the OK button 1105 of the front panel 1100is pressed down, the program display unit 1202 a notifies an identifierof the “Channel 2” to the reproduction unit 1202 b.

Also, the program display unit 1202 a memorizes the displaying programinformation in the primary storage unit 511 from the head end 101 on aregular basis via the POD 504. Generally speaking, acquirement of theprogram information from the head end takes time. When the EPG button1107 of the input unit 513 is pressed down, a program chart can bequickly displayed by displaying the program information pre-stored inthe primary storage unit 511.

The reproduction unit 1202 b reproduces a channel using the receivedidentifier of the channel. Relationship between the channel identifierand the channel is pre-stored in the secondary storage unit 510 aschannel information. FIG. 14 is an example of channel information storedin the secondary storage unit 510. The channel information is stored ina tabular form. A column 1401 is a channel identifier. A column 1402 isa channel name. A column 1403 is tuning information. The tuninginformation here includes frequencies, transmission rates, coding rates,etc., which are values provided to the QAM demodulation unit 501. Acolumn 1404 is a program number. The program number here is a numberthat identifies PMT stipulated in the MPEG2 standard. PMT will beexplained later. Each line from the line 1411 to the line 1414 is a setof each channel identifier, channel name and tuning information. Theline 1411 is a set that includes “1” as the identifier, “Channel 1” asthe channel name, a frequency “150 MHz” for the tuning information and“101” as the program number. For reproducing the channel, thereproduction unit 1202 b passes the received channel identifier to theservice manager as it is.

Also, when the user presses down the up cursor 1101 and the down cursor1102 during reproduction, the reproduction unit 1202 b receives thepressed notification via the CPU 514 from the input unit 513 and changesthe channel being reproduced. At first, the reproduction unit 1202 bmemorizes, in the primary storage unit 511, an identifier of the channelcurrently being reproduced. FIG. 15(1), FIG. 15(1) and FIG. 15(3) areexamples of identifiers of channels stored in the primary storage unit511. FIG. 15(1) shows an identifier “3” is memorized, and with referenceto FIG. 14, it shows that a channel of a channel name called “TV 3” isbeing reproduced. In a situation of FIG. 15(1), when the user pressesdown the up cursor 1101, the reproduction unit 1202 b refers to thechannel information of FIG. 14 and passes an identifier “2” of a channelname “Channel 2” to the service manager for switching the channel toreproduce a channel name called “Channel 2”, which is a previous channelin the chart. At the same time, the channel identifier “2” memorized inthe primary storage unit 511 is rewritten. FIG. 15(2) shows a situationthat the channel identifier is rewritten. Also, in a state of FIG.15(1), when the user presses down the down cursor 1102, the reproductionunit 1202 b refers to channel information in FIG. 14, and passes anidentifier “4” of a channel name called “TV Japan” to the service managefor switching the channel to reproduce the channel name called “TVJapan”, which is a next channel in the chart. At the same time, thechannel identifier “4” memorized in the primary storage unit 511 isrewritten. FIG. 15(3) shows a state when the channel identifier isrewritten.

Java VM 1203 is a Java virtual machine that consecutively analyzes andexecutes a program described in a Java™ language. The program describedin the Java language is compiled into intermediate codes called as bytecodes, which are not depended on hardware. The lava virtual machine isan interpreter that executes these byte codes. Also, a part of the Javavirtual machine translates the byte codes into an execution format,which is comprehensive to the CPU 514, and passes it to the CPU 514,which executes it. Java VM 1203 is started when the kernel 1201 aspecifies the Java program to be executed. In the present embodiment,the kernel 1201 a specifies the service manager 1204 as a Java programto be executed. Details of the Java language are described in many bookssuch as a book called “Java Language Specification (ISBN0-201-63451-1)”. Its details are omitted here. Also, detailed actionstaken by lava VM itself are described in many books such as a bookcalled “Java Virtual Machine Specification (ISBN 0-201-63451-X)”. Itsdetails are omitted here.

The service manager 1204 is a lava program written in the Java language,and consecutively executed by the Java VM 1203. It is possible for theservice manager 1204 to call up or to be called by other subprogramsthat are not described in the Java language, via JNI (lava NativeInterface). JNI is also described in many books such as a book called“Java Native Interface”. Its details are omitted here.

The service manager 1204 receives a channel identifier from thereproduction unit 1202 b via the JNI.

The service manager 1204 at first passes the channel identifier to atuner 1205 c located in the Java library 1205 and requests for tuning.The tuner 1205 c refers to channel information memorized in thesecondary storage unit 510 and acquires tuning information. Now, whenthe service manager 1204 passes a channel identifier “2” to the tuner1205 c, the tuner 1205 c refers to a line 1412 in FIG. 14, and acquirescorresponding tuning information “156 MHz”. The tuner 1205 c passes thetuning information to the QAM demodulation unit 501 via the library 1201b of the OS 1201. According to the provided tuning information, the QAMdemodulation unit 501 demodulates a signal sent from the head end 101,and passes it to the POD 504.

Next, the service manager 1204 requests descrambling to CA 1205 d in thelava library 1205. The CA 1205 d provides information necessary fordescramble to the POD 504 via the library 1201 b of OS 1201. Based onthe information provided, the POD 504 descrambles the signal providedfrom the QAM demodulation unit 501 and passes it to the TS decoder 505.

Next, the service manager 1204 provides an identifier of the channel toIMF 1205 a in the lava library 1205, and requests reproduction of videoand audio.

At first, the IMF 1205 a acquires a packet ID from PAT and PMT forspecifying the video and the audio to be reproduced. PAT and PMT aretables describing program structure in the MPEG2 transport stream, whichis stipulated in the MPEG2 standards. They are embedded in the payloadof the packet included in the MPEG2 transport stream, and sent with theaudio and the video. Please see the standard manual for its details.Only the outline is explained here. PAT is an acronym of ProgramAssociation Table, stored in the packet of the packet ID “0” and sent.To acquire PAT, the JMF1205 a designates the packet ID “0” and the CPU514 to the TS decoder 505 via the library 1201 b of OS1201. The IMF 1205a collects packets of PAT by having the TS decoder 505 execute afiltering process with the packet ID “0” and pass it to the CPU 514.FIG. 16 is a table describing a typical example of PAT informationcollected. A column 1601 is a program number. A column 1602 is a packetID. The packet ID in the column 1602 is used to acquire PMT. Lines 1611to 1613 are a set of a program number of the channel and itscorresponding packet ID. Three channels are defined here in this table.A set of a program number “101” and a packet ID “501” is defined in aline 1611. Suppose the channel identifier provided to the IMF 1205 a is“2”, the JMF 1205 a acquires “102” as its corresponding program numberwith reference to a line 1412 in FIG. 14, and then acquires a packet ID“502” corresponding to the program number “102” with reference to theline 1612 in the PAT described in FIG. 14. The PMT is an abbreviation ofProgram Map Table, which is stored in the packet of the packet IDstipulated by the PAT and sent. To acquire the PMT, the IMF 1205 adesignates the packet ID and the CPU 514 to the TS decoder 505 via thelibrary 1201 b of OS 1201. Suppose the packet ID designated here is“502”. The IMF 1205 a collects packets of PMT by having the TS decoder505 execute a filtering process with the packet ID “502” and pass it tothe CPU 514. FIG. 17 is a table describing a typical example of PMTinformation collected. A column 1701 is a stream type, and a column 1702is a packet ID. In a packet of the packet ID designated by the column1702, information designated by the stream type is stored in a payloadand sent. A column 1703 is supplemental information. Columns 1711 to1714 are a set of a packet ID called as an elementary stream and a typeof information being sent. The column 1711 is a set of a stream type“audio” and a packet ID “5011”, which shows that audio is stored in apayload of the packet ID “5011”. The JMF 1205 a acquires packet IDs ofvideo and audio reproduced from the PMT. With reference to FIG. 17, theJMF 1205 a acquires a packet ID “5011” for audio from the line 1711, anda packet ID “5012” for video from the line 1712.

Next, the IMF 1205 a provides a set of the acquired audio packet ID andan audio decoder 506 as its output destination and the acquired videopacket ID and a video decoder 508 as its output destination to the TSdecoder 505 via the library 1201 b of the OS 1201. The TS decoder 505executes a filtering process based on the provided packet IDs and theiroutput destinations. Here, the packet of the packet ID “5011” isprovided to the audio decoder 506, and the packet of the packet ID“5012” is provided to the video decoder 508. The audio decoder 506executes digital-analogue conversion for the packet provided, andreproduces the audio via a speaker 507. The video decoder 508 stores thevideo data, which is embedded in the packet of the MPEG2 transportstream provided from the TS decoder 505, into a video buffer 517.

According to an enlargement and reduction command directed from the CPU514, the video enlargement and reduction unit 520 enlarges or reducesthe data stored in the video buffer 517 and passes it to the composingunit 523.

According to the Z order directed from the CPU 514, the composing unit523 superposes the data provided from the video enlargement andreduction unit 520, the data provided from the still enlargement andreduction unit 521, and the data provided from the OSD enlargement andreduction unit 522, and outputs it to the display 509.

Finally, the service manager 1204 provides a channel identifier to theAM 1205 b located in the Java library 1205, and requests databroadcasting reproduction. The data broadcasting reproduction here meansto extract a Java program contained in the MPEG2 transport stream and tohave the lavaVM 1203 execute the program. Regarding a method to embed aJava program into the MPEG2 transport stream, a method called as DSMCCdescribed in an MPEG standard document ISO/IEC 13818-6 is used. Itsdetailed explanation for DSMCC is omitted here. The DSMCC methodstipulates a method for encoding a file system, which is made up of adirectory and a file used in a computer, into a packet of the MPEG2transport stream. Also, the information of the Java program executed ina style called AIT is embedded into the packet of the MPEG2 transportstream and sent. The AIT is an abbreviation of Application InformationTable, which is defined in Chapter 10 of DVB-MHP standard (formally,ETSI TS 101 812 DVB-MHP specifications V1.0.2).

The AM 1205 b at first acquires the PAT and the PMT in the same way asthe JMF 1205 a for acquiring the AIT, and then acquires the packet ID ofthe packet where the AIT is stored. Suppose an identifier of theprovided channel is “2” now, and the PAT in FIG. 16 and the PMT in FIG.17 are sent, it acquires the PMT in FIG. 17 in the same procedures asthe one for the JMF 1205 a. The AM 1205 b extracts a packet ID, whichhas “data” as its stream type and “AIT” as its supplemental information,from the elementary stream. With reference to FIG. 17, the AM 1205 bacquires the packet ID “5013” since the elementary stream in the line1713 is applicable.

The AM 1205 b provides the packet ID of the AIT and the CPU 514 as itsoutput destination to the TS decoder 505 via the library 1201 b of theOS 1201. A filtering process is executed with the TS decoder 505 and theprovided packet ID, and a processed outcome is passed to the CPU 514. Asa result of this, the AM1205 b can collect the packet of the AIT. FIG.18 is a table, which describes a typical example of the AIT informationcollected. A column 1801 is an identifier of the Java program. A column1802 is control information of the Java program. There are “autostart”,“present”, “kill”, etc. as the control information. The “autostart”means that a terminal apparatus 500 automatically and immediatelyexecutes this program, the “present” means that the terminal apparatus500 does not automatically execute the program, and the “kill” meansthat the terminal apparatus 500 stops the program. A column 1803 is aDSMCC identifier for extraction a packet ID containing the Java programin a DSMCC method. A column 1804 is a program name of the Java program.The lines 1811 and 1812 are a set of the Java program information. TheJava program defined in the line 1811 is a set of an identifier “301”,control information “autostart”, a DSMCC identifier “1”, and a programname “a/TopXlet”. The Java program defined in the line 1812 is a set ofan identifier “302”, control information “present”, a DSMCC identifier“1”, and a program name “b/GameXlet”. These Java programs here containthe same DSMCC identifier. It means that two Java programs are containedin a file system that is encoded in one DSMCC method. Although only fourtypes of information are stipulated for the Java program here, therewill be more information defined in practice. Please see DVB-MHPstandards for details.

The AM 1205 b finds out the lava program of “autostart” within the AIT,and extracts its corresponding DSMCC identifier and lava program name.With reference to FIG. 18, the AM 1205 b extracts the Java program inthe line 1811, and acquires the DSMCC identifier “1” and the Javaprogram name “a/TopXlet”.

Next, the AM 1205 b acquires the packet ID of the packet, which storesthe Java program in the DSMCC method, from the PMT using the DSMCCidentifier acquired from the AIT. To be more specific, the AM 1205 bacquires the packet ID of the elementary stream, which has “data” as itsstream type and a matching DSMCC identifier in the supplementalinformation.

Suppose that the DSMCC identifier is now “1”, and the PMT is just asdescribed in FIG. 17, the elementary stream in a line 1714 is matchedwith the condition so that the packet ID “5014” is extracted.

The AM 1205 b designates a packet ID of the packet, where data isembedded into the TD decoder 505 in the DSMCC method, and the CPU 514 asits output destination via the library 1201 b of the OS 1201. The packetID “5014” is provided here. A filtering process is executed with the TSdecoder 505 and the provided packet ID and its processed outcome ispassed to the CPU 514. As a result of this, the AM 1205 b can collectnecessary packets. The AM 1205 b restores a file system according to theDSMCC method from the collected packets, and stores it in the primarystorage unit 511. Hereinafter, actions to take out the data such as filesystems from the packet in the MPEG2 transport stream and to store it ina memorizing mean such as the primary storage unit 511 are referred toas “download”.

FIG. 19 is an example of a file system downloaded. In the figure, acircle indicates a directory, a square indicates a file, 1901 is a rootdirectory, 1902 is a directory “a”, 1903 is a directory “b”, 1904 is afile “TopXlet.class”, and 1905 is a file “GameXlet.class”.

Next, the AM 1205 b passes the Java program executed from the filesystem downloaded to the primary storage unit 511 to the JavaVM 1203.Suppose the Java program name executed now is “a/TopXlet”, a file“a/TopXlet.class” where “.class” is added to an end of the Java programname is the file to be executed. “/” is a delimiter of a directoryand/or a file name, which is the Java program that should be executed bythe file 1904 with reference to FIG. 19. Next, the AM 1205 b providesthe file 1904 to the Java VM 1203.

The Java VM 1203 executes the provided Java program.

Once the service manager 1204 receives an identifier of another channel,it stops execution of the Java program and video and audio, which arebeing reproduced through each library contained in the Java library1205, and via each library contained in the same Java library 1205,conducts the Java program and reproduced video and audio based on thenewly received channel identifier.

The Java library 1205 is a set of a plural number of Java librariesstored in a ROM 512. In the present embodiment, the Java library 1205here contains JMF 1205 a, AM 1205 b, Tuner 1205 c, CA 1205 d, POD Lib1205 e, a resolution switching unit 1205 f, AWT 1205 g, STL 1205 h, etc.

The POD Lib 1205 e provides functions to acquire information from thePOD 504 and to control the POD 504 via the library 1201 b and the CPU514.

The resolution switching unit 1205 f provides a function to control thevideo decoder 508, the video enlargement and reduction unit 520, thestill decoder 515, the still enlargement and reduction unit 521, the OSDenlargement and reduction unit 516, and the OSD enlargement andreduction unit 522 through the CPU 514. Details are described later.

The AWT 1205 g accepts a rendering instruction from the Java program.Based on the accepted instruction, the AWT 1205 g draws characters andgraphics in the OSD buffer by sending necessary information to the OSDcontrolling unit 516. As a specific example for a rendering process,there is a process for rendering a line or rendering a square, which isa publicly known technology realized in a class and interfacespecifications stipulated in a lava.awt package. Therefore, its detailedexplanation is omitted here. Note that when drawing characters andgraphics, the AWT 1205 g may once obtain the off-screen memory from theprimary storage unit 511, and transfer the contents of the off screen tothe OSD controlling unit 516 after drawing characters and graphics inthe obtained off-screen buffer.

The STL 1205 h accepts MPEG-I frame data displayed from the lava programand its display position. The STL 1205 h passes the accepted MPEG-Iframe data and its display position to the still decoder 515. The stilldecoder 515 decodes the MPEG-I frame data to the provided displayposition, and stores it into the still buffer 518. By doing so, the Javaprogram can draw pictures in the still buffer.

FIG. 24 is a flowchart related to a video display process. The TSdecoder 505 transfers video data to the video decoder 508 (S2401). Thevideo decoder 508 decodes the transferred video data, and stores itsoutcome into the video buffer 517 (S2402). The video decoder 508 decideswhether there is an instruction of enlargement and reduction regardingthe video display from the CPU 514 or not (S2403). If there is theinstruction of enlargement and reduction, the video enlargement andreduction unit 520 executes the enlargement and reduction process to thedata being stored in the video buffer 517 (S2404), and transfers it tothe composing unit 523 (S2405). If there is no instruction ofenlargement and reduction, the video enlargement and reduction unit 520transfers the data being stored in the video buffer 517 to the composingunit 523 (S2405).

FIG. 25 is a flowchart related to a still display process. MPEG2-I framedata is provided from the CPU 514 to the still decoder 515 (S2501). Thestill decoder 515 decodes the provided MPEG2-I frame data, and storesthe outcome into the still buffer 518 (S2502). The still decoder 515decides whether there is an instruction of enlargement and reductionregarding the still display from the CPU 514 (S2503). When there is theinstruction of enlargement and reduction, the still enlargement andreduction unit 521 executes the enlargement and reduction process to thedata being stored in the still buffer 518 (S2504), and it transfers itto the composing unit 523 (S2505). When there is no instruction ofenlargement and reduction, the still enlargement and reduction unit 521transfers the data being stored in the still buffer 518 to the composingunit 523.

FIG. 26 is a flowchart related to the display process of OSD. Characterand graphics data is provided from the CPU 514 to the OSD controllingunit 516 (S2601). The OSD controlling unit 516 builds up the video inthe OSD buffer 519 based on the provided characters and graphics data(S2602). The OSD controlling unit 516 decides whether there is aninstruction of enlargement and reduction related to the display of OSDfrom the CPU 514 (S2603). If there is the instruction of enlargement andreduction, the OSD enlargement and reduction unit 522 executes theenlargement and reduction process to the data being stored in the OSDbuffer 519 (S2604), and transfers it to the composing unit 523 (S2605).If there is no instruction of enlargement and reduction, the OSDenlargement and reduction unit 522 transfers the data being stored inthe OSD buffer 519 to the composing unit 523.

Here, the image of enlargement and reduction is explained with referenceof an example. Like 2801 of FIG. 28, when data of 720 pixels in widthand 480 pixels in height is enlarged in size, i.e. enlarged to 960pixels in width and 540 pixels in height, it becomes just as shown in2802 of FIG. 28.

FIG. 27 is a flowchart related to a composing process for the videogenerated in the flowchart shown in FIG. 24, the still generated in theflowchart shown in FIG. 25 and the OSD generated in the flowchart shownin FIG. 26. The composing unit 523 decides whether there is a changeinstruction of Z order from the CPU 514 (S5901) or not. If there is achange instruction, it decides which of buffers, the video buffer 517,the still buffer 518 or the OSD buffer 519 is applicable to the firstbuffer 5701, the second buffer 5702 and the third buffer 5703 accordingto the change instruction (S5902). If there is no change instruction,the previous Z order is followed. A combination of the Z order is one offix pattern combinations as indicated in FIG. 58. Next, the composingunit 523 decides which of the buffers, the video buffer 517, the stillbuffer 518 or the OSD buffer 519 is applicable to the buffer relevant tothe third buffer, which is located at the furthest back (S5903). Whenthe buffer is the video buffer 517, video data is composed in thecomposing unit 523 (S5904). When the buffer is the still buffer 518,still data is composed in the composing unit 523 (S5905). When thebuffer is the OSD buffer 519, OSD data is composed in the composing unit523 (S5906). For example, for a case that the image of composed data is2901 of FIG. 29, the image after the composing process is just as 3001of FIG. 30. Next, the composing unit 523 decides which of the buffers,the video buffer 517, the still buffer 518 or the OSD buffer 519 isapplicable to the buffer relevant to the second buffer (S5907). When thebuffer is the video buffer 517, video data is composed in the composingunit 523 (S5908). When the buffer is the still buffer 518, still data iscomposed in the composing unit 523 (S5909). When the buffer is the OSDbuffer 519, OSD data is composed in the composing unit 523 (S5910). Forexample, when the image of the composed data is 2902 of FIG. 29, theimage after the composing process is just as shown in 3002 of FIG. 30.Next, the composing unit 523 decides which of the buffers, the videobuffer 517, the still buffer 518 or the OSD buffer 519 is applicable tothe buffer relevant to the first buffer, which is located at theforeground (S5911). When the buffer is the video buffer 517, video datais composed in the composing unit 523 (S5912). When the buffer is thestill buffer 518, still data is composed in the composing unit 523(S5913). When the buffer is the OSD buffer 519, OSD data is composed inthe composing unit 523 (S5914). For example, for a case that the imageof composed data is 2903 of FIG. 29, the image after the composingprocess is just as shown in 3003 of FIG. 30. Finally, a result of thecomposing process is output and displayed on the display 509 (S5915).

The following explains downloading and saving the lava program as wellas display actions of the Java program.

The service manager 1204 conducts interactive communications with thehead end 101 through the POD Lib1205 e contained in the lava library1205. This interactive communication is realized by using the QPSKdemodulation unit 502 and the QPSK modulation unit 503 via the library1201 b and the POD 504 of the OS 1201.

The service manager 1204 receives Java program information, which shouldbe saved by the terminal apparatus 500 in the secondary storage unit510, from the head end 101 by using this communication. This informationcalled as XAIT information. The XAIT information is sent in adiscretional form between the head end 101 and the POD 504. Whatever thesending form is chosen, the present invention is executable as long asthe information necessary for the XAIT is contained.

FIG. 20 is a chart describing a typical example of the XAIT informationobtained from the head end 101. A column 2001 is a Java programidentifier. A column 2002 is control information of the Java program.There is “autoselect”, “present” and so on as the control information,and “autoselect” means to execute this program automatically when theterminal apparatus 500 is powered on, and “present” means not to executethis program. A column 2003 is a DSMCC identifier for extracting apacket ID containing the Java program in the DSMCC method. A column 2004is a program name of the Java program. A column 2005 is a priority ofthe Java program. Lines 2011 and 2012 are a set of Java programinformation. The Java program defined in the line 2011 is a set of theidentifier “701”, the control information “autoselect”, the DSMCCidentifier “1”, the program name “a/Banner1Xlet”. Here, there are fivetypes of information stipulated for the Java program. However, thepresent invention is executable even if more information is defined.

When the service manager 1204 receives the XAIT information, it saves afile system in the primary storage unit 511 from the MPEG2 transportstream in the same procedure as the procedure to download the Javaprogram from the AIT information. And then, the file system saved iscopied to the secondary storage unit 510. However, it is also possibleto download the file system directly to the secondary storage unit 510without having the process done through the primary storage unit 511.Next, the service manager 1204 saves XAIT information in the secondarystorage unit 510 by linking it to a storage location of the downloadedfile system. FIG. 21 shows an example of how the XAIT information andthe downloaded file system are linked and saved in the secondary storageunit 510. Explanation for elements in FIG. 21 having the same number asthose elements in FIG. 20 is omitted here. A column 2101 stores a savinglocation of the corresponding file system downloaded. In the diagram,the saving location is indicated with a column. 2110 is the downloadedfile system, which internally holds a top directory 2111, a directory“a” 2112, a directory “b” 2113, a file “Banner1Xlet.class” 2114 and afile “Banner2Xlet.class” 2115.

Here, the XAIT information is saved after the Java program is saved.However, the XAIT information may be saved before the Java program issaved.

After the terminal 500 is turned on, the OS 1201 designates the servicemanager 1204 to the JavaVM 1203. After the JavaVM 1203 activates theservice manager 1204, the service manager 1204 at first refers to theXAIT information saved in the secondary storage unit 510. Here, theservice manager 1204 refers to the control information of each Javaprogram, provides the program of “autoselect” to the JavaVM 1203 andactivates it. With reference to FIG. 21, the Java program “Banner1Xlet”defined in the line 2011 is activated.

Once the Java program “Banner1Xlet” is activated, the Java program“Banner1Xlet” designates to display an OSD to the CPU 514 when the Javaprogram “Banner1Xlet” displays characters and graphics. The CPU 514provides the characters and the graphics to the OSD controlling unit516, and the OSD display process is executed, and finally the OSD buffer519 is composed with the video buffer 517 and the still buffer 518, andthe resultant is displayed on the display 509.

Next, the following describes a video resolution switching function,which is the main function of the present invention. FIG. 31 is aconfiguration diagram of the video resolution switching function.

An application program 3100 is, for example, an application such as aJava program called “Banner1Xlet”.

A resolution switching unit 1205 f contains an OSD resolution managingunit 3101, a video resolution managing unit 3102, a still resolutionmanaging unit 3103, a video format resolution change detecting unit 3104and a resolution selection deciding unit 3105, and serves as a videoresolution switching function.

The OSD resolution managing unit 3101 manages the resolution of the OSDbuffer 519. The OSD resolution managing unit 3101 has a function toaccept a change request of the current resolution of the OSD buffer 519from the application program 3100, and a function to notify a change inthe resolution of the OSD buffer 519 to the application program 3100.When the change request of the resolution of the OSD buffer 519 isaccepted, the OSD resolution managing unit 3101 notifies it to theresolution selection deciding unit 3105.

The video resolution managing unit 3102 manages the resolution of thevideo buffer 517. The video resolution managing unit 3102 has a functionto accept a change request of the current resolution of the video buffer517 from the application program 3100, and a function to notify a changein the resolution of the video buffer 517 to the application program3100. When the change request of the resolution of the video buffer 517is accepted, the video resolution managing unit 3102 notifies it to theresolution selection deciding unit 3105.

The still resolution managing unit 3103 manages the resolution of thestill buffer 518. The still resolution managing unit 3103 has a functionto accept a change request of the current resolution of the still buffer518 from the application program 3100, and a function to notify a changein the resolution of the still buffer 518 to the application program3100. When the change request of the resolution of the still buffer 518is accepted, the still resolution managing unit 3103 notifies it to theresolution selection deciding unit 3105.

When the resolution of the video format received by the video decoder508 is different from the resolution of the video format previouslydecoded, the video format resolution change detecting unit 3104 notifiesit to the resolution selection deciding unit 3105.

The resolution selection deciding unit 3105 selects the resolution ofeach buffer considering a combination of buffers that can be displayedon the TV receiver when one of the following cases occurs: a case thereis a change request for the current resolution of the OSD buffer 519 tothe OSD resolution managing unit 3101; a case there is a change requestfor the current resolution of the video buffer 517 to the videoresolution managing unit 3102; a case there is a change request for thecurrent resolution of the still buffer 518 to the still resolutionmanaging unit 3103; or a case there is a change request of theresolution of the video format from the video format resolution changedetecting unit 310. The following explains the combinations that can bedisplayed. The TV receiver is in three layered structure, i.e. the OSDbuffer 519 that displays characters and graphics, the video buffer 517that displays video, and the still buffer 518 that displays stillimages, and there are displayable combinations of these buffers. Forexample, combinations such as those described in FIG. 60 and FIG. 61 areavailable. While the TV receiver displays each of the buffers in acombination of 2 (6002) indicated in FIG. 60, the video resolution ofthe video format received by the video decoder 508 may be changed to1920 pixels in width and 1080 pixels in height and the screen ratio ofthat may be changed to 16:9. If that is the case, the resolution of eachbuffer may be changed to a combination 4 (6004) according to the videoformat. The combinations of each buffer indicated in FIG. 60 and FIG. 61are memorized in the secondary storage unit 510, the primary storageunit 511 or the ROM 512. Suppose that the combinations of each bufferare now stored in the ROM 512, it means that the resolution selectiondeciding unit 3105 refers to the ROM 512 when considering the bestcombination to be displayed, and selects the most optimum combinationaccording to a specific set of rules from the available combinations.

FIG. 62 and FIG. 63 are flowcharts showing the operation of theresolution selection deciding unit 3105 in the case where the OSDresolution managing unit 3101 receives a change request for changing thecurrent resolution of the OSD buffer 519. The OSD resolution managingunit 3101 passes the OSD resolution to the resolution selection decidingunit 3105 to make a change request (S6201). The resolution selectiondeciding unit 3105 stores, into the primary storage unit 511, the OSDresolution which is requested to be changed (S6202). Next, theresolution selection deciding unit 3105 inquires of the video resolutionmanaging unit 3102 about the current video resolution so as to obtain it(S6203). Then, the resolution selection deciding unit 3105 tries toselect, from plural combinations of OSD buffer resolution and videobuffer resolution shown in FIG. 60 and FIG. 61, a set that matches theOSD resolution requested to be changed and the current video resolution(S6204). Then, the resolution selection deciding unit 3105 decideswhether the selection in S6204 is possible or not (S6205).

When deciding in S6205 that the selection is possible, the resolutionselection deciding unit 3105 conducts an OSD resolution changenotification to the OSD resolution managing unit 3101 (S6304).

Meanwhile, when deciding in S6205 that the selection is not possible,the resolution selection deciding unit 3105 tries to select, from pluralcombinations shown in FIG. 60 and FIG. 61, a set that matches theresolution of the OSD buffer and the OSD resolution requested to bechanged. (S6206). Next, the resolution selection deciding unit 3105compares the video resolution in the selected set with the current videoresolution to see if they match or not, and decides whether the videoresolution is to be changed or not (S6207). Only when deciding in S6207that the video resolution is to be changed, the resolution selectiondeciding unit 3105 conducts a video resolution change notification tothe video resolution managing unit 3102 (S6208). Next, the resolutionselection deciding unit 3105 inquires of the still resolution managingunit 3103 about the current still resolution so as to obtain it (S6301).Then, the resolution selection deciding unit 3105 compares the stillresolution in the selected set with the current still resolution to seeif they match or not, and decides whether the still resolution is to bechanged or not (S6302). Only when deciding in S6301 that the stillresolution is to be changed, the resolution selection deciding unit 3105conducts a still resolution change notification to the still resolutionmanaging unit 3103 (S6303). Then, the resolution selection deciding unit3105 conducts an OSD resolution change notification to the OSDresolution managing unit 3101 (S6304).

Here, when the changed resolution of the video buffer 517 is differentfrom the resolution of the video decoded by the video decoder 508, thevideo decoder 508 enlarges or reduces the video in accordance with thechanged resolution of the video buffer 517, and stores the resultantinto the video buffer 517.

According to the resolution of the OS buffer, the video enlargement andreduction unit 520 enlarges or reduces the video data stored in thevideo buffer 517. Assuming that a set that includes the changedresolutions is a combination 8 (6104) shown in FIG. 61, for example, theresolution of the OSD buffer 519 is 960*540, and the resolution of thevideo buffer 517 and the resolution of the still buffer 518 are1920*1080. Therefore, the video enlargement and reduction unit 520reduces the video data stored in the video buffer 517 from 1920*1080 to960*540, and the still enlargement and reduction unit 521 reduces thestill data stored in the still buffer 518 from 1920*1080 to 960*540. Asa result, the resolutions of video, still, and OSD become the same,making it possible for the composing unit 523 to perform composingprocessing.

Note that, in the above examples, although the video enlargement andreduction unit 520 and the still enlargement and reduction unit 521perform enlargement or reduction processing in accordance with theresolution of the OSD buffer 519, it is also possible that the stillenlargement and reduction unit 521 and the OSD enlargement and reductionunit 522 perform enlargement or reduction processing in accordance withthe resolution of the video buffer 517, or that the video enlargementand reduction unit 520 and the OSD enlargement and reduction unit 522perform enlargement or reduction processing in accordance with theresolution of the still buffer 518.

As described above, the displayable combinations of resolutions for thevideo buffer 517, the still buffer 518 and the OSD buffer 519 containenlargement and reduction information that stipulates actions of thevideo enlargement and reduction unit 520, the still enlargement andreduction unit 521 and the OSD enlargement and reduction unit 522. Or,the enlargement and reduction information may be memorized explicitly inthe secondary storage unit 510, the primary storage unit 511, the ROM512, etc. by associating the information to the displayable combinationsof resolutions for the video buffer 517, the still buffer 518, and theOSD buffer 519. The enlargement and reduction information may bespecifically defined respectively for each of the video enlargement andreduction unit 520, the still enlargement and reduction unit 521 and theOSD enlargement and reduction unit 522. Or, it may be stipulated ascommon resolution that should be output to the composing unit 523 by thevideo enlargement and reduction unit 520, the still enlargement andreduction unit 521 and the OSD enlargement and reduction unit 522. Also,by adding a common resolution designating unit that designates thiscommon resolution, the resolution of the video, the OSD and the still,which are output to the composing unit 523, may be easily changed. Forthe common resolution designating unit here, the resolution may bedesignated by an application program or designated by the resolutionselection deciding unit 3105.

Also, the resolution selection deciding unit 3105 directs enlargementand reduction to the video enlargement and reduction unit 520, the stillenlargement and reduction unit 521 and the OSD enlargement and reductionunit 522.

FIG. 64 and FIG. 65 are flowcharts of the resolution selection decidingunit 3105 for a case that the resolution of the video format received bythe video decoder 508 is different from the resolution of the videoformat that has been decoded before. The video format resolution changedetecting unit 3104 notifies the video format resolution change to theresolution selection deciding unit 3105 (S6401).

The resolution selection deciding unit 3105 tries to select, from pluralcombinations of OSD buffer resolution and video buffer resolution shownin FIG. 60 and FIG. 61, a set that matches the notified video formatresolution and the OSD resolution that is requested to be changed andthat is stored in the primary storage unit 511 (S6402). Then, theresolution selection deciding unit 3105 decides whether the selection inS6402 is possible or not (S6403), and only when deciding in S6403 thatthe selection is not possible, the resolution selection deciding unit3105 tries to select, from the combinations shown in FIG. 60 and FIG.61, a set that matches the resolution of the OSD buffer and the OSDresolution that is requested to be changed and that is stored in theprimary storage unit 511 (S6404).

Next, the resolution selection deciding unit 3105 inquires of the videoresolution managing unit 3102 about the current video resolution so asto obtain it (S6405). Then, the resolution selection deciding unit 3105compares the video resolution in the selected set with the current videoresolution to see if they match or not, and decides whether the videoresolution is to be changed or not (S6406). Only when deciding in S6406that the video resolution is to be changed, the resolution selectiondeciding unit 3105 conducts a video resolution change notification tothe video resolution managing unit 3102 (S6407).

Next, the resolution selection deciding unit 3105 inquires of the stillresolution managing unit 3103 about the current still resolution so asto obtain it (S6501). Then, the resolution selection deciding unit 3105compares the still resolution in the selected set with the current stillresolution to see if they match or not, and decides whether the stillresolution is to be changed or not (S6502). Only when deciding in S6502that the still resolution is to be changed, the resolution selectiondeciding unit 3105 conducts a still resolution change notification tothe still resolution managing unit 3103 (S6503).

Furthermore, as the operation of the resolution selection deciding unit305 in the case where the resolution of the video format received by thevideo decoder 508 is different from the resolution of the previouslydecoded video format, the contents of the flowcharts shown in FIG. 66and FIG. 67 may be employed.

The video format resolution change detecting unit 3104 conducts a videoresolution change notification to the resolution selection deciding unit3105 (S6601).

The resolution selection deciding unit 3105 inquires of the OSDresolution managing unit 3101 about the current OSD resolution so as toobtain it (S6602). Then, the resolution selection deciding unit 3105tries to select, from plural combinations of OSD buffer resolution andvideo buffer resolution shown in FIG. 60 and FIG. 61, a set that matchesthe notified video format resolution and the current OSD resolution(S6603). Then, the resolution selection deciding unit 3105 decideswhether the selection in S6603 is possible or not (S6604).

When deciding in S6604 that the selection is possible, the resolutionselection deciding unit 3105 inquires of the video resolution managingunit 3102 of the current video resolution so as to obtain it (S6605).Next, the resolution selection deciding unit 3105 compares the videoresolution in the selected set with the current video resolution to seeif they match or not, and decides whether the video resolution is to bechanged or not (S6606). Only when deciding in S6606 that the videoresolution is to be changed, the resolution selection deciding unit 3105conducts a video resolution change notification to the video resolutionmanaging unit 3102 (S6607). Next, the resolution selection deciding unit3105 inquires of the still resolution managing unit 3103 about thecurrent still resolution so as to obtain it (S6701). Then, theresolution selection deciding unit 3105 compares the still resolution inthe selected set with the current still resolution to see if they matchor not, and decides whether the still resolution is to be changed or not(S6702). Only when deciding in S6702 that the still resolution is to bechanged, the resolution selection deciding unit 3105 conducts a stillresolution change notification to the still resolution managing unit3103 (S6703).

FIG. 68 is a flowchart in the case where the OSD resolution managingunit 3101 receives a resolution change notification. The OSD resolutionmanaging unit 3101, upon receipt of a resolution change notification(S6801), passes the changed OSD resolution to the OSD controlling unit516 (S6802). The OSD controlling unit 516 stores such changed OSDresolution into the OSD buffer 519, and transfers the OSD data to theOSD buffer 519, which stores it (S6803). In order to compose the OSDbuffer 519, the video buffer 517 and the still buffer 518, the OSDresolution managing unit 3101 passes an enlargement/reduction ratio tothe OSD enlargement and reduction unit 522 (S6804). The OSD enlargementand reduction unit 522 enlarges or reduces the OSD data stored in theOSD buffer 519 using the passed enlargement/reduction ratio (S6805).Note that it is also possible that the OSD resolution managing unit 3101stores the changed OSD resolution into the OSD buffer 519, and the OSDcontrolling unit 516 refers to the OSD resolution stored in the OSDbuffer 519 so as to transfer the OSD data.

FIG. 69 is a flowchart in the case where the video resolution managingunit 3102 receives a resolution change notification. The videoresolution managing unit 3102, upon receipt of a resolution changenotification (S6901), passes the changed video resolution to the videodecoder 508 (S6902). The video decoder 508 stores, into the video buffer517, such changed video resolution as well as video data that has beendecoded using the changed video resolution (S6903). In order to composethe OSD buffer 519, the video buffer 517 and the still buffer 518, thevideo resolution managing unit 3102 passes an enlargement/reductionratio to the video enlargement and reduction unit 520 (S6904). The videoenlargement and reduction unit 520 enlarges or reduces the video datastored in the video buffer 517 using the passed enlargement/reductionratio (S6905). Note that it is also possible that the video resolutionmanaging unit 3102 stores the changed video resolution into the videobuffer 517, and the video decoder 508 refers to such video resolutionstored in the video buffer 517 so as to decode the video data.

FIG. 70 is a flowchart in the case where the still resolution managingunit 3103 receives a resolution change notification. The stillresolution managing unit 3103, upon receipt of a resolution changenotification (S7001), passes the changed still resolution to the stilldecoder 515 (S7002). The still decoder 515 stores, into the still buffer518, such changed still resolution as well as still data which it hasdecoded using the changed still resolution (S7003). In order to composethe OSD buffer 519, the video buffer 517 and the still buffer 518, thestill resolution managing unit 3103 passes an enlargement/reductionratio to the still enlargement and reduction unit 521 (S7004). The stillenlargement and reduction unit 521 enlarges or reduces the still datastored in the still buffer 518 using the passed enlargement/reductionratio (S7005). Note that it is also possible that the still resolutionmanaging unit 3103 stores the changed still resolution into the stillbuffer 518, and the still decoder 515 refers to such still resolutionstored in the still buffer 518 so as to decode the still data.

For example, suppose that the application program 3100 is an applicationthat displays a video display in a small area and displays anapplication display in its entire display area. To be more specific, JMF1205 a provides functions to enlarge and reduce the video and designateits display location, and the application program 3100 uses thesefunctions. In this case, as shown in FIG. 39, an OSD display area 3901,which is the display of the application, occupies the major portion of adisplay screen 3900, and a video display area 3902 is small. The sizeand ideographic location of the video display area 3902 are decidedaccording to the functions provided by the JMF 1205 a. In this case,when the video format is changed, it is desirable that the resolutionselection deciding unit 3105 changes the combination according to thecurrently displayed OSD resolution. The reason is because the video hasalready been reduced and displayed in the application of which videoquality is apparently deteriorated. Even if the resolution of the OSDbuffer 519 is changed according to the change in the video planeresolution, it is inevitable to deteriorate the quality of the video. Onthe other hand, it is necessary for the application program 3100 toredraw the OSD display area 3901 according to the change in theresolution of the OSD buffer 519. In general, a rendering process for alarger display area takes time. Also, it is necessary to prepare aplural number of characters and graphics information according to theresolution of the OSD buffer 519, which requires a lot of memories. Inaddition to it, the application program 3100 must be well-functioned todeal with complicated processes. Therefore, if the application program3100 explicitly issues a change request of desired OSD resolution to theOSD resolution managing unit 3101, it means that the OSD resolution isprioritized. As a result of this, there would be issues such ascomplications of the application program 3100 and how to retain extracharacters and graphics data. Also, when the resolution of the OSDbuffer 519 is prioritized, the video enlargement and reduction unit 520enlarges and reduces the video stored in the video buffer 517 to meetwith the resolution retained.

Eighth Embodiment

In the seventh embodiment, when two applications indicated in FIG. 38and FIG. 39 are being executed at the same time, it is necessary todecide which of the applications should be prioritized. In the presentembodiment, the structure of the resolution switching unit 1205 f shallbe the structure in FIG. 56. Since the structural components having thesame number as hose in the FIG. 31 have the same function, theirexplanation is omitted here. A change permitting unit 5601 permits achange request of the application program 3100. The application program3100 obtains change permission from the change permitting unit 5601before making a change request of the resolution to the OSD resolutionmanaging unit 5602, the video resolution managing unit 5603, and thestill resolution managing unit 5604. After the permission is obtained,it makes the necessary change request. If the change request becomesunnecessary, it notifies that the permission is no longer necessary tothe change permitting unit 5601. When other application makes apermission request after the permission is issued, the change permittingunit 5601 compares which of two applications has a higher priority anddecides which of the applications is permitted. In terms of thepriorities of applications, the change permitting unit 5601 may refer tothe priorities pre-assigned to the applications, which is as explainedin the example of FIG. 20 in the seventh embodiment, or the applicationprogram 3100 may provide such information to the change permitting unit5601. The OSD resolution managing unit 5602, the video resolutionmanaging unit 5603 and the still resolution managing unit 5604, inaddition to functions of the OSD resolution managing unit 3101, thevideo resolution managing unit 3102 and the still resolution managingunit 3103, do not accept a request from the application program 3100,which is not permitted by the change permitting unit 5601. By realizingthe present embodiment, it becomes possible to clarify which applicationa request is coming from, and therefore to run plural applicationsconcurrently.

The following practical use becomes possible through the embodiments 1,2, 3, 4, 5, 6, 7, and 8.

The present invention is applicable if it is used in any informationapparatuses such as a personal computer or a portable telephone.

Also, the POD 504 is detachable in the embodiments, but it is alsopossible to have a built-in configuration. When it is built in, the CPU706 of the POD 504 may be detached and the CPU 514 may also serve as theCPU 706.

The Java program registered in the POD Lib1205 e can be executed notonly in the Java program downloaded, but also in the Java program, whichis built in advance. Also, a slot unit may also be catered for adetachable memory media such as an SD memory card so that it is possibleto install the Java program from there. Also, it is possible to installa network unit connected to the network, and obtain the Java programfrom the network.

Additionally, by having the second storage unit 510 store the contentsstored in the ROM 512, it is possible to eliminate the ROM 512. Also,the secondary storage unit 510 can be made up of multiple sub secondarystorage units, and may have each of individual multiple sub secondarystorage units store different information. For example, it is possibleto divide the information into pieces as follows. One of the subsecondary storage units stores tuning information only, and another subsecondary storage unit stores the library 1201 b of the OS 1201, andadditionally other sub secondary storage unit stores the Java programdownloaded.

Also, though the registered Java program is stored in the secondarystorage unit 510 in the embodiments, it is possible to have it stored inthe primary storage unit 511. When it is stored in the primary storageunit 511, the information stored is completely deleted when the power isturned off.

Furthermore, the video enlargement and reduction unit 520, and the stillenlargement and reduction unit 521 and the OSD enlargement and reductionunit 520 are supposed to pass the result of enlargement and reductionprocesses as it is to the composing unit 523, however it is possible toadd a secondary video enlargement and reduction unit buffer, a secondarystill buffer and a secondary OSD buffer, and have the video enlargementand reduction unit 520, the still enlargement and reduction unit 521 andthe OSD enlargement and reduction unit 522 store the result ofenlargement and reduction processes in the secondary video enlargementand reduction unit buffer, the secondary still buffer and the secondaryOSD buffer, and the composing unit 523 read and compose the contentsfrom the secondary video enlargement and reduction unit buffer, thesecondary still buffer and the secondary OSD buffer.

According to the resolution switching apparatus of the presentinvention, the resolution switching apparatus comprises: a graphicsgenerating unit operable to generate graphics; a video generating unitoperable to output received video; a video resolution detecting unitoperable to detect resolution of the received video; a resolution setstorage unit operable to memorize a resolution set having resolution ofthe graphics and resolution of the video as a set; a resolution setselecting unit operable to select, from the resolution set storage unit,the resolution set based on the video resolution detected by the videoresolution detecting unit; and a composing unit operable to compose thegraphics and the received video based on the resolution set selected bythe resolution set selecting unit, and output the composed outcome, andthereby it is possible to compose the video and the graphics and todisplay in into one.

Additionally, the resolution switching apparatus further comprises avideo resolution change detecting unit operable to detect a change inthe received video resolution, wherein the resolution set selecting unitselects the resolution set when the video resolution change detectingunit detects the change in the received video resolution, and thereby adecision process for the resolution does not have to be done anytime anda volume of processes can be reduced.

Also, the present invention is the resolution switching apparatuswherein the resolution set storage unit memorizes only a resolution setthat can be composed by the composing unit, and thereby it is possibleto avoid any situation that a composing process cannot be pursued.

Furthermore, the present invention is the resolution switching apparatuswherein the resolution set selecting unit selects, from the resolutionset storage unit, a resolution set including video resolution detectedby the video resolution detecting unit, and thereby it can maintain abeautiful display by displaying the video as it is.

In addition, the present invention is the resolution switching unitwherein the resolution set selecting unit selects a resolution set whosegraphics resolution does not change, and thereby it is possible to avoidsome situation where graphics is reduced too much to see due to a changein the resolution or some distortion occurs due to a change in a rationof length and width, and a beautiful graphics display can be maintained.

Moreover, the resolution switching unit further comprises: anapplication executing unit operable to execute an application; and arendering execution accepting unit operable to accept a renderinginstruction from the application, wherein the graphics generating unitgenerates graphics according to the rendering instruction accepted bythe rendering execution accepting unit, and thereby the graphics andvideo generated by the application can be composed and output.

Also, the resolution switching apparatus further comprises a resolutionset change notifying unit operable to notify a change in the resolutionset to the application when the resolution set selecting unit selectsthe resolution, and thereby the application can recognizes the change inthe resolution so that it can redisplay the graphics according to theresolution.

And, the resolution switching apparatus further comprises a graphicsresolution change notifying unit operable to notify a change in thegraphics resolution to the application in a case where the graphicsresolution is changed when the resolution set selecting unit selects theresolution, and thereby the application can recognizes only the changein the graphics resolution. Therefore, it can efficiently redisplay thegraphics according to the resolution.

Furthermore, the resolution switching apparatus further comprises avideo resolution change notifying unit operable to notify a change inthe video resolution to the application for a case the video resolutionis changed when the resolution set selecting unit selects theresolution, and thereby the application can execute a process, etc. todisplay the video better, which is enlarged or reduced by using the lavaclass library.

In addition to it, the resolution switching apparatus further comprisesa graphics resolution change request accepting unit operable to accept achange request of the graphics resolution from the application, whereinthe resolution set selecting unit selects the resolution set based onthe graphics resolution accepted by the graphics resolution changerequest accepting unit, and thereby it can display with the graphicsresolution desired by the application.

Also, the present invention is the resolution switching apparatuswherein the resolution set selecting unit selects the resolution setincluding the graphics resolution accepted by the graphics resolutionchange request accepting unit, and thereby it can display with thegraphics resolution desired by the application.

Additionally, the resolution switching apparatus further comprises avideo resolution change request accepting unit operable to accept achange request for the video resolution from the application, andwherein the resolution set selecting unit selects the resolution setbased on the video resolution accepted by the video resolution changerequest accepting unit, and thereby it can display the video with theresolution desired by the application.

Also, the present invention is the resolution switching apparatuswherein the resolution set selecting unit selects the resolution setincluding the video resolution accepted by the video resolution changerequest accepting unit, and thereby it can display the video with theresolution desired by the application.

Moreover, the resolution switching apparatus further comprises: agraphics enlargement and reduction unit operable to enlarge or reducegraphics generated by the graphics generating unit; and a videoenlargement and reduction unit operable to enlarge or reduce the videooutput by the video generating unit, wherein the composing unit composesthe graphics and the video enlarged or reduced by the graphicsenlargement and reduction unit and the video enlargement and reductionunit, and thereby the graphics and the video can be composed to have thesame resolution and displayed beautifully.

Also, the resolution switching apparatus further comprises anenlargement and reduction resolution designating unit operable todesignate resolution of the graphics and of the video generated byenlargement or reduction through the graphics enlargement and reductionunit and the video enlargement and reduction unit, and thereby thegraphics and the video can be converted into the desired resolution andcomposed and displayed beautifully.

In addition, the present invention is the resolution switching apparatuswherein the resolution set storage unit retains resolution, which isrealized by enlargement or reduction by the graphics enlargement andreduction unit and the video enlargement and reduction unit, bycorresponding the resolution to the resolution set, and thereby it ispossible to clearly designate resolution before conversion andresolution after conversion. As a result of it, an enlargement andreduction process with less deterioration, e.g. enlargement andreduction of an integral multiple, and beautiful composed results anddisplay are achieved.

Also, the resolution switching apparatus further comprises a priorityresolution set storage unit operable to memorize a priority resolutionset, which is a preferable combination of the graphics and the video,wherein the priority set selecting unit selects the resolution set basedon the priority resolution set memorized in the priority resolution setstorage unit, and thereby a combination of more beautifully displayableresolution is prioritized and displayed.

Also, the resolution switching apparatus further comprises a priorityresolution set storage unit operable to memorize a priority resolutionset, which is a preferable combination of the graphics and the video,wherein the resolution set selecting unit selects the resolution setbased on the priority resolution set memorized in the priorityresolution set storage unit in a case where the resolution set includingthe video resolution detected by the resolution detecting unit cannot beselected from the resolution set storage unit, and thereby resolution ofthe video should be maintained. However, if it is not possible, abeautiful display can be achieved by using the combination of theresolution registered as a backup.

And, the resolution switching apparatus further comprises a priorityresolution set storage unit operable to memorize a priority resolutionset, which is a preferable combination of the graphics and the video,wherein the resolution set selecting unit selects the resolution setbased on the priority resolution set memorized in the priorityresolution set storage unit in a case where the resolution set that doesnot change the graphics resolution cannot be selected, and therebyresolution of the video should be maintained. However, if it is notpossible, a beautiful display can be achieved by using the combinationof the resolution registered as a backup.

Also, the resolution switching apparatus further comprises a videoresolution change detecting unit operable to detect a change in thereceived video resolution, wherein the resolution set selecting unit,when the video resolution change detecting unit detects the change inthe received video resolution, selects the resolution set including thegraphics resolution accepted by the graphics resolution change requestaccepting unit right before the video resolution change detecting unitdetects the change, and thereby it is possible to maintain theresolution of the graphics previously designated by the application, andalso automatically maintain the graphics display of the application.

And, the resolution switching apparatus further comprises a videoresolution change detecting unit operable to detect a change in thereceived video resolution, wherein the resolution set selecting unitselects the resolution set including the received video resolution whenthe video resolution change detecting unit detects a change in thereceived video resolution and the graphics resolution change requestaccepting unit does not accept a request to change the graphicsresolution, and thereby resolution of the video is considered to beprioritized since the application does not designate resolution of thegraphics. A beautiful display can be automatically maintained byoutputting the video resolution with the resolution of the video whichis input.

Also, the resolution switching apparatus comprises: a graphicsgenerating unit operable to generate graphics; a video generating unitoperable to output received video; a still generating unit operable tooutput a still image; a video resolution detecting unit operable todetect resolution of the received video; a resolution set storage unitoperable to memorize a resolution set having resolution of the graphics,resolution of the video and resolution of the still image as a set; aresolution set selecting unit operable to select the resolution set fromthe resolution set storage unit based on the video resolution detectedby the video resolution detecting unit; and a composing unit operable tocompose the graphics, the received video and the still image based onthe resolution set selected by the resolution set selecting unit, andoutput the composed outcome, and thereby it is possible to compose thevideo, the graphics and the still image, and display it.

Additionally, the resolution switching unit further comprises: anapplication executing unit operable to execute an application; and arendering execution accepting unit operable to accept a renderinginstruction from the application, wherein the graphics generating unitgenerates graphics according to the rendering instruction accepted bythe rendering executing accepting unit, and thereby plane resolution,which is the main entity of the display, can be maintained, and abeautiful display can be kept.

And, the resolution switching unit further comprises: an applicationexecuting unit operable to execute an application; and a renderingexecution accepting unit operable to accept a rendering instruction fromthe application, wherein the graphics generating unit generates graphicsaccording to the rendering instruction accepted by the renderingexecuting accepting unit, and thereby the graphics, the video and thestill image generated by the application can be composed and displayed.

Also, the resolution switching unit further comprises a still imageresolution change request accepting unit operable to accept a changerequest of the still image resolution from the application, and whereinthe resolution set selecting unit selects the resolution set based onthe still image resolution accepted by the still image resolution changerequest accepting unit, and thereby resolution of the still image can bekept, and a beautiful still image can be maintained.

Moreover, the present invention is the resolution switching unit whereinthe resolution set selecting unit selects the resolution set includingthe still image resolution accepted by the still image resolution changerequest accepting unit, and thereby resolution of the still image can bekept, and a beautiful still image can be maintained.

Also, the resolution switching unit further comprises a still imagechange request permitting unit operable to permit the change request ofthe still image resolution, wherein the still image resolution changerequest accepting unit accepts the change request of the still imageresolution only from the application for which a change request ispermitted by the still image change request permitting unit, and therebyacceptance of requests from a plural number of applications can beexclusively controlled. By doing so, it is possible to avoid a flickerof the display screen caused by the plural number of applications thatfrequently switch resolution of the still image.

Additionally, the resolution switching unit further comprises a graphicschange request permitting unit operable to permit the change request ofthe graphics resolution, wherein the graphics resolution change requestaccepting unit accepts the change request of the graphics resolutiononly from the application for which a change request is permitted by thegraphics change request permitting unit, and thereby it is possible toavoid a flicker of the display screen caused by a plural number ofapplications that frequently switch resolution of the still image.

Also, the resolution switching unit further comprises a video changerequest permitting unit operable to permit the change request of thevideo resolution, wherein the video resolution change request acceptingunit accepts the change request of the video resolution from theapplication for which a change request is permitted by the video changerequest permitting unit, and thereby it is possible to avoid a flickerof the display screen caused by a plural number of applications thatfrequently switch resolution of the still image.

Also, the present invention is a computer readable recording medium inwhich a program is recorded to perform each function of: a graphicsgenerating unit operable to generate graphics; a video generating unitoperable to output received video; a video resolution detecting unitoperable to detect resolution of the received video; a resolution setstorage unit operable to memorize a resolution set having resolution ofthe graphics and resolution of the video as a set; a resolution setselecting unit operable to select the resolution set from the resolutionset storage unit based on the video resolution detected by theresolution detecting unit; and a composing unit operable to compose thegraphics and the received video based on the resolution set selected bythe resolution set selecting unit, and output the composed outcome, andthereby enhances its portability.

As the industrial applicability of the present invention, it is possibleto use the present invention as an apparatus and the like that displaysvideo and graphics, e.g. a television receiver terminal and the likethat receives an interactive program thorough a digital broadcasting,and more particularly as an apparatus and the like that displays video,graphics, and a still image, changing their resolutions appropriately.

Although only some exemplary embodiments of this invention have beendescribed in detail above, those skilled in the art will readilyappreciate that many modifications are possible in the exemplaryembodiments without materially departing from the novel teachings andadvantages of this invention. Accordingly, all such modifications areintended to be included within the scope of this invention.

1. A display processing method performed by a display processingapparatus including a composer that composes graphics with video andoutputs a result of the composition, comprising: holding graphics with aresolution requested by an application; holding video with apredetermined resolution, the video being received via digital broadcastand being decoded; determining whether to enlarge or reduce the graphicsin order to compose the graphics with the held video; and composing theenlarged or reduced graphics with the held video, and outputting aresult of the composition by the composer, wherein when a format of thereceived video is changed during the outputting of the result of thecomposition, the resolution of the held video to be composed is changedbased on the change of the format of the received video, whether theresolution of the graphics should be changed in response to the changeof the resolution of the held video based on the change of the videoformat of the received video is judged by referring to a list indicatingcombinations of permitted graphics resolutions and video resolutions,when the resolution of the graphics corresponding to the changedresolution of the held video is indicated in the list, the resolution ofthe graphics is changed to the resolution of the graphics correspondingto the changed resolution of the held video, the changing of theresolution of the graphics is notified to the application, and thegraphics, whose resolution has been changed and which is to be composed,is enlarged or reduced so that the graphics, whose resolution has beenchanged and which is to be composed, can be composed with the held videowhose resolution has been changed based on the change of the format ofthe received video, and that the result of the composition can beoutputted.
 2. A display processing apparatus for composing graphics withvideo and outputting a result of the composition, comprising: a firstholder that holds graphics with a resolution requested by anapplication; a second holder that holds video with a predeterminedresolution, the video being received via digital broadcast and beingdecoded; a determiner that determines whether to enlarge or reduce thegraphics in order to compose the graphics with the held video; and acomposer that composes the enlarged or reduced graphics with the heldvideo; a storage unit that stores a list indicating combinations ofpermitted graphics resolutions and video resolutions; and an outputterthat outputs a result of the composition, wherein the display processingapparatus is configured so that when a format of the received video ischanged during the outputting of the result of the composition, theresolution of the held video to be composed is changed based on thechange of the format of the received video, whether the resolution ofthe graphics should be changed in response to the change of theresolution of the changed held video based on the change of the videoformat of the received video is judged by referring to the list, whenthe resolution of the graphics corresponding to the changed resolutionof the held video is indicated in the list, the resolution of thegraphics is changed to the resolution of the graphics corresponding tothe changed resolution of the held video, the changing of the resolutionof the graphics is notified to the application, and the graphics, whoseresolution has been changed and which is to be composed, is enlarged orreduced so that the graphics, whose resolution has been changed andwhich is to be composed, can be composed with the held video of whoseresolution has been changed based on the change of the format of thereceived video, and that the result of the composition can be outputted.